Bump webfactory/ssh-agent from v0.5.0 to v0.5.1

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>

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     - uses: actions/checkout@v2.3.4
     - uses: coursier/cache-action@v6
     - run: sbt -v test makeSite
-    - uses: webfactory/ssh-agent@v0.5.0
+    - uses: webfactory/ssh-agent@v0.5.1
       if: ${{ !github.event.repository.fork && github.ref == 'refs/heads/main' && github.event_name == 'push' }}
       with:
         ssh-private-key: ${{ secrets.DEPLOY_KEY_1 }}