chore: Push version changes to the release branch (#6)

Previously, since no remote and branch was specified, it was attempting
to push to the main branch, and failing since the main branch is
protected. This updates the CI workflow so that the version number
update is pushed to the release branch.

.github/workflows/ci.yaml

@@ -56,4 +56,4 @@ jobs:
         git config user.email "48985810+david-letterman@users.noreply.github.com"
         git add anthropic.go
         git commit -m "Configure version number"
-        git push
+        git push origin release-please--branches--main