chore(ci): only bump minor on main

Author: strantalis

release-please_main-branch.json

@@ -2,6 +2,7 @@
   "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
   "release-type": "maven",
   "bump-minor-pre-major": true,
+  "versioning": "always-bump-minor",
   "separate-pull-requests": false,
   "include-component-in-tag": false,
   "group-pull-request-title-pattern": "chore(${branch}): release ${version}",