Update System.Collections.Immutable to 9.0.11

[Copilot]

Updates System.Collections.Immutable from 8.0.0 to 9.0.11 in eng/Versions.props to align with the latest stable 9.0 release.

Changes

• Bumped SystemCollectionsImmutableVersion from 8.0.0 to 9.0.11

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[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• 80zvsblobprodcus35.vsblob.vsassets.io
  • Triggering command: /home/REDACTED/work/diagnostics/diagnostics/.dotnet/dotnet /home/REDACTED/work/diagnostics/diagnostics/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:true /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=false /home/REDACTED/.nuget/packages/microsoft.dotnet.arcade.sdk/10.0.0-beta.25603.103/tools/Build.proj /p:Configuration=Debug /p:RepoRoot=/home/REDACTED/work/diagnostics/diagnostics/ /p:Restore=true /p:Build=true /p:DotNetBuild=false /p:DotNetBuildSourceOnly=false /p:DotNetBuildFromVMR=false /p:Rebuild=false /p:Test=false (dns block)
• kgfvsblobprodcus314.vsblob.vsassets.io
  • Triggering command: /home/REDACTED/work/diagnostics/diagnostics/.dotnet/dotnet /home/REDACTED/work/diagnostics/diagnostics/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:true /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=false /home/REDACTED/.nuget/packages/microsoft.dotnet.arcade.sdk/10.0.0-beta.25603.103/tools/Build.proj /p:Configuration=Debug /p:RepoRoot=/home/REDACTED/work/diagnostics/diagnostics/ /p:Restore=true /p:Build=true /p:DotNetBuild=false /p:DotNetBuildSourceOnly=false /p:DotNetBuildFromVMR=false /p:Rebuild=false /p:Test=false (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)