Dependabot should not trigger CI

Dependabot's PRs need to use the PR label workflow.

They are now push events, but have a read-only Github token:
https://github.blog/changelog/2021-02-19-github-actions-workflows-triggered-by-dependabot-prs-will-run-with-read-only-permissions/

(also rename all workflows so filenames match workflow names)

.github/workflows/ci.yaml → .github/workflows/quarks-operator-ci.yaml

@@ -50,7 +50,10 @@ jobs:
     runs-on: ubuntu-16.04
 
     # Cannot run for pushes in forked repos, without adapting this workflow
-    if: github.repository == 'cloudfoundry-incubator/quarks-operator'
+    # dependabots pushes directly now, but needs PR review since secrets are missing
+    if: >
+      github.repository == 'cloudfoundry-incubator/quarks-operator' &&
+      !contains(["dependabot"], "${{ github.actor }}")
 
     steps:
     - name: Set up Go