chore(main): release 6.1.0-alpha (#22)

Release-As: 6.1.0-alpha

Author: github-actions[bot]

release-please-config.json

@@ -8,9 +8,7 @@
       "bump-minor-pre-major": false,
       "bump-patch-for-minor-pre-major": false,
       "draft": false,
-      "prerelease-type": "alpha",
-      "prerelease": true,
-      "versioning": "prerelease"
+      "prerelease": true
     }
   },
   "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json"