[release/9.0] Suppress SYSLIB5005 for System.Formats.Nrbf as experimental

[github-actions]

Backport of #12156 to release/9.0

/cc @lonitra @jeffhandley

Customer Impact

We are marking the System.Formats.Nrbf APIs as [Experimental] in .NET 9 to leave the door open for making API changes in the next release. Since WinForms consumes these APIs, we need to suppress the diagnostic that will occur.

Testing

Created a local build of System.Formats.Nrbf with the assembly marked as [Experimental], consumed that build into the WinForms solution for all references, and found the projects that need to have the suppression in place.

Risk

Low. Suppressing a diagnostic that will be introduced in RC2.

Microsoft Reviewers: Open in CodeFlow

[jeffhandley]

I got confirmation from @carlossanlop that we can skip this PR and only backport into release/9.0-rc2 with #12162. Automation will automatically flow RC2 fixes into the GA branch.

[carlossanlop]

@jeffhandley I do not know if the dotnet/winforms repo has the same rule of auto flowing release/9.0-rc2 PRs to release/9.0. My suggestion only applied to dotnet/runtime.

@lonitra do you know if you have a bot that autoflows RC2 changes to the GA branch?

[lonitra]

Reopening. We do not have automation where checkins from rc2 branch will flow into release/9.0

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.81790%. Comparing base (17a488b) to head (f0c5a07).
Report is 3 commits behind head on release/9.0.

Additional details and impacted files

@@                  Coverage Diff                  @@
##           release/9.0      #12161         +/-   ##
=====================================================
+ Coverage     74.81314%   74.81790%   +0.00475%     
=====================================================
  Files             3022        3022                 
  Lines           630138      630138                 
  Branches         46785       46785                 
=====================================================
+ Hits            471426      471456         +30     
+ Misses          155331      155300         -31     
- Partials          3381        3382          +1     

Flag	Coverage Δ
Debug	74.81790% <ø> (+0.00475%)	⬆️
integration	18.03398% <ø> (+0.00353%)	⬆️
production	47.83604% <ø> (+0.01054%)	⬆️
test	97.00759% <ø> (ø)
unit	44.86519% <ø> (+0.00913%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.