Bump Gu.Roslyn.Asserts from 4.2.0 to 4.2.1

Bumps [Gu.Roslyn.Asserts](https://github.com/GuOrg/Gu.Roslyn.Asserts) from 4.2.0 to 4.2.1.
- [Release notes](https://github.com/GuOrg/Gu.Roslyn.Asserts/releases)
- [Changelog](https://github.com/GuOrg/Gu.Roslyn.Asserts/blob/master/RELEASE_NOTES.md)
- [Commits](https://github.com/GuOrg/Gu.Roslyn.Asserts/commits)

---
updated-dependencies:
- dependency-name: Gu.Roslyn.Asserts
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

ReflectionAnalyzers.Tests/ReflectionAnalyzers.Tests.csproj

@@ -26,7 +26,7 @@
 
   <ItemGroup>
     <PackageReference Include="Gu.Analyzers" Version="2.0.2" PrivateAssets="all" />
-    <PackageReference Include="Gu.Roslyn.Asserts" Version="4.2.0" />
+    <PackageReference Include="Gu.Roslyn.Asserts" Version="4.2.1" />
     <PackageReference Include="Gu.Roslyn.Asserts.Analyzers" Version="4.0.0" PrivateAssets="all" />
     <PackageReference Include="IDisposableAnalyzers" Version="4.0.2" PrivateAssets="all" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" PrivateAssets="all" />