[release/7.0-staging] [mono] Fix GetCustomAttributes System.Reflection API with a custom attribute provider

[github-actions]

Backport of #94602 to release/7.0-staging

/cc @ivanpovazan

Customer Impact

ASP.NET test suite uses GetCustomAttributes API with a custom attribute provider: https://github.com/dotnet/aspnetcore/blob/402e7fc10aa304775f50d318c8a4dafbf46dbfe0/src/Shared/PropertyAsParameterInfo.cs#L15 which was not properly supported by Mono causing about 100 failing tests, as reported here: #94437 (comment)

This PR fixes the issue.

Testing

This PR includes a unit test which verifies the fix that should pass on CI.

Risk

Low.

IMPORTANT: If this backport is for a servicing release, please verify that:

• The PR target branch is release/X.0-staging, not release/X.0.

• If the change touches code that ships in a NuGet package, you have added the necessary package authoring and gotten it explicitly reviewed.

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Issue Details

---

Backport of #94602 to release/7.0-staging

/cc @ivanpovazan

Customer Impact

Testing

Risk

IMPORTANT: If this backport is for a servicing release, please verify that:

• The PR target branch is release/X.0-staging, not release/X.0.

• If the change touches code that ships in a NuGet package, you have added the necessary package authoring and gotten it explicitly reviewed.

Author:	github-actions[bot]
Assignees:	-
Labels:	area-System.Reflection
Milestone:	-

[ivanpovazan]

The added test has successfully passed on CI.
The other CI failures are unrelated.

This is safe to be merged.

[carlossanlop]

@ivanpovazan @lambdageek did this get Tactics approval? Today's code complete.

[carlossanlop]

I'm flowing staging to internal now, so the branches are closed. This will have to wait until the January release.

[steveisok]

Per tactics, this change unfortunately doesn't meet the bar in terms of customer impact. @ivanpovazan if you find this blocks customers in a significant way, please identify and reopen.