Bump System.Collections.Immutable from 9.0.0 to 9.0.1

Bumps [System.Collections.Immutable](https://github.com/dotnet/runtime) from 9.0.0 to 9.0.1.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v9.0.0...v9.0.1)

---
updated-dependencies:
- dependency-name: System.Collections.Immutable
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Directory.Packages.props

@@ -7,7 +7,7 @@
     <PackageVersion Include="NUnit.Analyzers" Version="4.6.0" />
     <PackageVersion Include="NUnit3TestAdapter" Version="4.6.0" />
     <PackageVersion Include="StyleCop.Analyzers" Version="1.2.0-beta.556" />
-    <PackageVersion Include="System.Collections.Immutable" Version="9.0.0" />
+    <PackageVersion Include="System.Collections.Immutable" Version="9.0.1" />
     <PackageVersion Include="CommandLineParser" Version="2.9.1" />
     <PackageVersion Include="BenchmarkDotNet" Version="0.14.0" />
     <PackageVersion Include="coverlet.msbuild" Version="6.0.3" />