Bump webfactory/ssh-agent from v0.5.0 to v0.5.1 (#6768)

Bumps [webfactory/ssh-agent](https://github.com/webfactory/ssh-agent) from v0.5.0 to v0.5.1.
- [Release notes](https://github.com/webfactory/ssh-agent/releases)
- [Changelog](https://github.com/webfactory/ssh-agent/blob/master/CHANGELOG.md)
- [Commits](webfactory/ssh-agent@v0.5.0...4b6f4eb)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build-and-deploy.yml

@@ -239,7 +239,7 @@ jobs:
           path: build
 
       - name: Setup SSH Keys and known_hosts
-        uses: webfactory/ssh-agent@v0.5.0
+        uses: webfactory/ssh-agent@v0.5.1
         with:
           ssh-private-key: ${{ secrets.PANTHEON_DEPLOY_KEY }}