Bump GitVersion.MsBuild from 6.7.0 to 6.8.0

---
updated-dependencies:
- dependency-name: GitVersion.MsBuild
  dependency-version: 6.8.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Directory.Packages.props

@@ -52,7 +52,7 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.14.0" />
   </ItemGroup>
   <ItemGroup Label="Versioning. Referenced CI-only from Directory.Build.props; matches the GitVersion config.">
-    <PackageVersion Include="GitVersion.MsBuild" Version="6.7.0" />
+    <PackageVersion Include="GitVersion.MsBuild" Version="6.8.0" />
   </ItemGroup>
   <ItemGroup Label="Global Package References, added to every project">
     <GlobalPackageVersion Include="ReferenceTrimmer" Version="3.1.22" PrivateAssets="All" />