Bump LibGit2Sharp from 0.30.0 to 0.31.0 in /Tools

Bumps [LibGit2Sharp](https://github.com/libgit2/libgit2sharp) from 0.30.0 to 0.31.0.
- [Release notes](https://github.com/libgit2/libgit2sharp/releases)
- [Changelog](https://github.com/libgit2/libgit2sharp/blob/master/CHANGES.md)
- [Commits](libgit2/libgit2sharp@0.30.0...0.31.0)

---
updated-dependencies:
- dependency-name: LibGit2Sharp
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Tools/CopyrightUpdateTool/CopyrightUpdateTool.csproj

@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="LibGit2Sharp" Version="0.30.0" />
+    <PackageReference Include="LibGit2Sharp" Version="0.31.0" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
   </ItemGroup>