config: workflow ordering

.github/workflows/build.yml

@@ -1,13 +1,11 @@
 name: "Build and populate cache"
 on:
   pull_request:
-  push:
-    branches:
-      - main
-  schedule:
-    - cron:  '51 2 * * *'
+    types: [labeled]
+
 jobs:
   tests:
+    if: ${{ github.event.label.name == 'formatted' }}
     strategy:
       matrix:
         cachixName:

.github/workflows/format.yml

@@ -13,6 +13,7 @@ jobs:
       # Give the default GITHUB_TOKEN write permission to commit and push the
       # added or changed files to the repository.
       contents: write
+      pull-requests: write
 
     steps:
     - name: Checkout repository
@@ -28,3 +29,15 @@ jobs:
       with:
         commit_message: "treewide: nixfmt formatting"
         branch: ${{ github.head_ref }}
+    - name: Add label
+      uses: actions/github-script@v6
+      with:
+        github-token: "${{ secrets.PAT }}"
+        script: |
+          github.rest.issues.addLabels({
+            issue_number: context.issue.number,
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            labels: ["formatted"]
+          })
+