[release/6.0-preview4] Update dependencies from dotnet/icu

[dotnet-maestro]

This pull request updates the following dependencies

From https://github.com/dotnet/icu

• Subscription: c277b9d4-03c5-4bfc-8d1e-08d90058d0d8
• Build: 20210416.1
• Date Produced: 4/16/2021 6:59 PM
• Commit: 313017d0effca6e8ade5fefc8e580224e65d8525
• Branch: refs/heads/release/6.0-preview4

• Updates:
  • Microsoft.NETCore.Runtime.ICU.Transport: from 6.0.0-preview.4.21212.2 to 6.0.0-preview.4.21216.1

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[mmitche]

@jeffschwMSFT I've seen these failures on a few PRs. Any ideas?

[jeffschwMSFT]

@agocke can you take a look, I see some apphost related failures on this PR.

[agocke]

Looking

[agocke]

@mateoatr Can you take a look? Looks like the symbolic link tests again. Can we just remove the deletion? Since the symbolic link is created in a test directory, shouldn't it be cleaned up after the test is done anyway?

[mateoatr]

Can we just remove the deletion? Since the symbolic link is created in a test directory, shouldn't it be cleaned up after the test is done anyway?

It should. I already removed the symlink deletion in #51373 although it's still causing problems when trying to publish the build logs in linux: #51502.

[mmitche]

@mateoatr Does that need to be ported to this p4 branch?

[agocke]

Ugh guess symlinks can't be reliably deleted like other files. Probably need to keep the deletion then but maybe use another pinvoke to do it. Maybe call 'unlink' or 'rm' directly?

[mateoatr]

@mateoatr Does that need to be ported to this p4 branch?

I think it should. I already opened #51568

Probably need to keep the deletion then but maybe use another pinvoke to do it. Maybe call 'unlink' or 'rm' directly?

Yeah. I'll try unlinking; that should fix the access permissions.

[agocke]

@mateoatr I tried File.Delete just to give it a shot.

[agocke]

@mmitche This is ready, I think.