Bump FsUnit from 5.0.5 to 5.1.0

Bumps [FsUnit](https://github.com/fsprojects/FsUnit) from 5.0.5 to 5.1.0.
- [Release notes](https://github.com/fsprojects/FsUnit/releases)
- [Changelog](https://github.com/fsprojects/FsUnit/blob/master/RELEASE_NOTES.md)
- [Commits](fsprojects/FsUnit@5.0.5...5.1.0)

---
updated-dependencies:
- dependency-name: FsUnit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

src/FSharp.Tests/FSharp.Tests.fsproj

@@ -36,7 +36,7 @@
     <ItemGroup>
         <PackageReference Include="NUnit" Version="3.13.3" />
         <PackageReference Include="NUnitLite" Version="3.13.3" />
-        <PackageReference Include="FsUnit" Version="5.0.5" />
+        <PackageReference Include="FsUnit" Version="5.1.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.0" />
         <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.3">
             <PrivateAssets>all</PrivateAssets>