GH actions: label to disable CI runs completely (#6677)

I don't want my very-early-draft PRs to trigger any CI runs.
So, add a label `run-no-ci`, and piggy-back on the `check-permissions` job.

.github/workflows/actionlint.yml

@@ -17,6 +17,7 @@ concurrency:
 
 jobs:
   actionlint:
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'run-no-ci') }}
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

.github/workflows/build_and_test.yml

@@ -26,8 +26,8 @@ env:
 
 jobs:
   check-permissions:
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'run-no-ci') }}
     runs-on: ubuntu-latest
-
     steps:
     - name: Disallow PRs from forks
       if: |

.github/workflows/neon_extra_builds.yml

@@ -117,6 +117,7 @@ jobs:
 
   check-linux-arm-build:
     timeout-minutes: 90
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'run-no-ci') }}
     runs-on: [ self-hosted, dev, arm64 ]
 
     env:
@@ -237,6 +238,7 @@ jobs:
 
   check-codestyle-rust-arm:
     timeout-minutes: 90
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'run-no-ci') }}
     runs-on: [ self-hosted, dev, arm64 ]
 
     container: