Downgrade rush because it is causing commandline args not to appear in npm run scripts

[kenotron]

Ever since we upgraded rush to 5.9.0, the --production (or indeed any flags from rush commands) are not passed down to the npm run scripts. So this makes us not build any minified or AMD builds. I'm downgrading to what we had before to keep building AMD bundles

Microsoft Reviewers: Open in CodeFlow

[msft-github-bot]

Component perf results:

Scenario	Target branch avg total (ms)	PR avg total (ms)	Target branch avg per item (ms)	PR avg per item (ms)	Is significant change	Is regression
ScenarioDefaultButton	42.673	42.363	0.427	0.424	false	false

[size-auditor]

Size Auditor did not detect a change in bundle size for any component!

[KevinTCoughlin]

Fixed in microsoft/rushstack#1334?

https://www.npmjs.com/package/@microsoft/rush/v/5.9.1

cc: @iclanton

[KevinTCoughlin]

Ok with downgrade to mitigate, but you might consider upgrading to 5.9.1 instead.

[kenotron]

Yeah, mitigate for now. 5.9.0 has a behavioral change that we need to consider before upgrading really:

(BEHAVIOR CHANGE) Fix an issue where CI jobs could succeed even if a task reported warnings to stderr; if your build fails due to warnings after upgrading, please see microsoft/rushstack#1329

Looks like we'd probably upgrade to pnpm 3 + rush >5.7.0 if we want to pursue this path. I think we should think through this a bit more before just taking latest.

[kenotron]

coordinating with @jdhuntington who will create another PR to bump everything for prod release

[iclanton]

FYI, 5.8.0 doesn't have the behavioral change, but does have additional fixes.