[New git-credential-manager version] GCM 2.5.1

[github-actions]

release: fix signing in release workflow (#1649)

Fix the `dotnet tool install` command for code signing in the release
workflow.

D'oh!

https://github.com/git-ecosystem/git-credential-manager/releases/tag/v2.5.1

[dscho]

/open pr

The workflow run was started