fix(Calendar): remove explicit readonly semantics from grid and gridcells

[smhigley]

Pull request checklist

• Addresses an existing issue: Fixes 12950
• Include a change request file using $ yarn change

Description of changes

This change comes from a past spec ambiguity on whether role="grid" was editable by default. NVDA used to read "editable" for any gridcell unless it was explicitly marked readonly. The issue is that Talkback is now treating any use of readonly as disabled, whether on form controls or grid.

Before making this change, I tested with NVDA 2021 on Chrome and Edge 94, and FF 93, and it appears NVDA is no longer announcing "editable" by default, so removing the aria-readonly attributes seems like the best choice now.

[fabricteam]

📊 Bundle size report

_{🤖 This report was generated against 25bf940e8e5512b0168999a7ae4c6994e4976129}

[size-auditor]

Asset size changes

Project	Bundle	Baseline Size	New Size	Difference
office-ui-fabric-react	fluentui-react-WeeklyDayPicker	94.502 kB	94.46 kB	-42 bytes
office-ui-fabric-react	fluentui-react-Calendar	113.129 kB	113.049 kB	-80 bytes
office-ui-fabric-react	fluentui-react-DatePicker	169.642 kB	169.562 kB	-80 bytes

 Over Tolerance (1024 B)  Over Baseline  Below Baseline  New   Removed 1 kB = 1000 B

Baseline commit: 25bf940e8e5512b0168999a7ae4c6994e4976129 (build)

[fabricteam]

Perf Analysis (@fluentui/react)

No significant results to display.

All results

Scenario	Render type	Master Ticks	PR Ticks	Iterations	Status
Avatar	mount	1031	1010	5000
BaseButton	mount	980	1017	5000
Breadcrumb	mount	2639	2595	1000
ButtonNext	mount	515	524	5000
Checkbox	mount	1644	1670	5000
CheckboxBase	mount	1403	1454	5000
ChoiceGroup	mount	5030	4968	5000
ComboBox	mount	1007	1074	1000
CommandBar	mount	10258	10322	1000
ContextualMenu	mount	6322	6572	1000
DefaultButton	mount	1199	1212	5000
DetailsRow	mount	3942	3933	5000
DetailsRowFast	mount	3977	3897	5000
DetailsRowNoStyles	mount	3781	3753	5000
Dialog	mount	2605	2522	1000
DocumentCardTitle	mount	185	185	1000
Dropdown	mount	3388	3443	5000
FluentProviderNext	mount	3212	3311	5000
FluentProviderWithTheme	mount	213	211	10
FluentProviderWithTheme	virtual-rerender	114	102	10
FluentProviderWithTheme	virtual-rerender-with-unmount	238	238	10
FocusTrapZone	mount	1921	1908	5000
FocusZone	mount	1872	1790	5000
IconButton	mount	1839	1889	5000
Label	mount	371	355	5000
Layer	mount	3184	3117	5000
Link	mount	513	522	5000
MakeStyles	mount	1756	1825	50000
MenuButton	mount	1544	1582	5000
MessageBar	mount	2024	1985	5000
Nav	mount	3466	3418	1000
OverflowSet	mount	1117	1157	5000
Panel	mount	2437	2467	1000
Persona	mount	888	885	1000
Pivot	mount	1553	1487	1000
PrimaryButton	mount	1354	1340	5000
Rating	mount	8348	8244	5000
SearchBox	mount	1515	1427	5000
Shimmer	mount	2692	2679	5000
Slider	mount	2092	2064	5000
SpinButton	mount	5211	5205	5000
Spinner	mount	438	453	5000
SplitButton	mount	3331	3348	5000
Stack	mount	540	524	5000
StackWithIntrinsicChildren	mount	1813	1814	5000
StackWithTextChildren	mount	5160	5086	5000
SwatchColorPicker	mount	11135	11102	5000
Tabs	mount	1518	1553	1000
TagPicker	mount	2773	2814	5000
TeachingBubble	mount	13040	13313	5000
Text	mount	456	452	5000
TextField	mount	1445	1479	5000
ThemeProvider	mount	1198	1235	5000
ThemeProvider	virtual-rerender	628	618	5000
ThemeProvider	virtual-rerender-with-unmount	1984	1991	5000
Toggle	mount	877	852	5000
buttonNative	mount	131	133	5000

Perf Analysis (@fluentui/react-northstar)

Perf tests with no regressions

Scenario	Current PR Ticks	Baseline Ticks	Ratio
AccordionMinimalPerf.default	199	176	1.13:1
ListNestedPerf.default	639	583	1.1:1
ListMinimalPerf.default	584	535	1.09:1
TableMinimalPerf.default	467	432	1.08:1
BoxMinimalPerf.default	389	363	1.07:1
PortalMinimalPerf.default	184	172	1.07:1
VideoMinimalPerf.default	692	646	1.07:1
AvatarMinimalPerf.default	216	203	1.06:1
IconMinimalPerf.default	683	645	1.06:1
TextMinimalPerf.default	381	358	1.06:1
ListCommonPerf.default	718	682	1.05:1
DropdownManyItemsPerf.default	755	728	1.04:1
GridMinimalPerf.default	376	363	1.04:1
InputMinimalPerf.default	1399	1363	1.03:1
ProviderMinimalPerf.default	1216	1178	1.03:1
RadioGroupMinimalPerf.default	492	476	1.03:1
RefMinimalPerf.default	241	233	1.03:1
TreeMinimalPerf.default	858	830	1.03:1
AlertMinimalPerf.default	324	318	1.02:1
AttachmentSlotsPerf.default	1161	1138	1.02:1
CarouselMinimalPerf.default	494	482	1.02:1
DividerMinimalPerf.default	402	393	1.02:1
HeaderMinimalPerf.default	392	384	1.02:1
LayoutMinimalPerf.default	406	399	1.02:1
MenuMinimalPerf.default	902	888	1.02:1
PopupMinimalPerf.default	608	598	1.02:1
StatusMinimalPerf.default	739	723	1.02:1
AnimationMinimalPerf.default	469	463	1.01:1
DropdownMinimalPerf.default	3322	3279	1.01:1
ItemLayoutMinimalPerf.default	1311	1297	1.01:1
SplitButtonMinimalPerf.default	4602	4566	1.01:1
TextAreaMinimalPerf.default	557	554	1.01:1
TooltipMinimalPerf.default	1109	1102	1.01:1
TreeWith60ListItems.default	197	195	1.01:1
ButtonMinimalPerf.default	207	207	1:1
ButtonOverridesMissPerf.default	1870	1875	1:1
ChatMinimalPerf.default	717	717	1:1
CheckboxMinimalPerf.default	2868	2870	1:1
FormMinimalPerf.default	459	459	1:1
ListWith60ListItems.default	683	685	1:1
CustomToolbarPrototype.default	4320	4305	1:1
DialogMinimalPerf.default	809	815	0.99:1
FlexMinimalPerf.default	300	304	0.99:1
LabelMinimalPerf.default	416	419	0.99:1
ProviderMergeThemesPerf.default	1717	1741	0.99:1
SegmentMinimalPerf.default	376	380	0.99:1
SliderMinimalPerf.default	1796	1809	0.99:1
TableManyItemsPerf.default	2046	2058	0.99:1
ToolbarMinimalPerf.default	975	985	0.99:1
ButtonSlotsPerf.default	568	577	0.98:1
ChatWithPopoverPerf.default	417	424	0.98:1
EmbedMinimalPerf.default	4520	4592	0.98:1
LoaderMinimalPerf.default	713	725	0.98:1
MenuButtonMinimalPerf.default	1738	1766	0.98:1
ReactionMinimalPerf.default	421	428	0.98:1
CardMinimalPerf.default	612	629	0.97:1
DatepickerMinimalPerf.default	5732	5911	0.97:1
HeaderSlotsPerf.default	818	855	0.96:1
RosterPerf.default	1258	1322	0.95:1
ChatDuplicateMessagesPerf.default	331	352	0.94:1
ImageMinimalPerf.default	417	443	0.94:1
AttachmentMinimalPerf.default	180	196	0.92:1
SkeletonMinimalPerf.default	389	426	0.91:1

[lorejoh12]

Thanks for following up on this! That is indeed the reason we originally had to add this readonly tag, so it's great to hear that it's been fixed and we can have a little more straightforward semantics here.