Chore: Migrate workflows to use create-github-app-token (#2142)

- Removes dependabot.yml as renovate will update grafana-sdk for us
- Migrates to `create-github-app-token`
- Pin workflows
- Removes is-compatible.yml I found that workflow not helping much but
creating an annoyingly long comment

Fixes https://github.com/grafana/oss-big-tent-squad/issues/144

.github/workflows/push.yaml

@@ -12,9 +12,9 @@ on:
 jobs:
   ci:
     name: CI
-    uses: grafana/plugin-ci-workflows/.github/workflows/ci.yml@main
+    uses: grafana/plugin-ci-workflows/.github/workflows/ci.yml@ci-cd-workflows/v4.3.0
     with:
-      go-version: '1.25'
-      golangci-lint-version: '2.4.0'
+      go-version: '1.25.5'
+      golangci-lint-version: '2.7.2'
       plugin-version-suffix: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || '' }}
       run-playwright: true