workflow: Add check-main-status workflow

The workflow checks the status of the main branch. When checks on main
are failing or pending the workflow should fail. This prevents
introducing more potenisal issues when main is already broken.

To skip the check when making a fix for main, add the fix-ci label to
the PR.

Signed-off-by: Gregers Gram Rygg <[email protected]>

.github/workflows/check-main-status.yml

@@ -0,0 +1,66 @@
+name: Check Main Branch Status
+on:
+  pull_request:
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: "Pull Request number"
+        required: true
+
+jobs:
+  check-main-status:
+    runs-on: ubuntu-24.04
+    env:
+      PR_NUMBER: ${{ github.event.number || github.event.inputs.pr_number }}
+    steps:
+      - name: Check if PR has 'fix-ci' label
+        id: has_fix_ci_label
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const labels = await github.rest.issues.listLabelsOnIssue({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: process.env.PR_NUMBER,
+            });
+
+            const hasFixCiLabel = labels.data.map(label => label.name).includes('fix-ci');
+            console.log(`Has 'fix-ci' label: ${hasFixCiLabel}`);
+
+            return hasFixCiLabel;
+
+      - name: Check Main Branch Status
+        if: ${{ steps.has_fix_ci_label.outputs.result == 'false' }}
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const mainRef = await github.rest.git.getRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: 'heads/main',
+            });
+
+            const mainSha = mainRef.data.object.sha;
+            console.log(`Main branch SHA: ${mainSha}`);
+
+            const checkRuns = await github.rest.checks.listForRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: mainSha,
+            });
+
+            console.log(`Check runs (${checkRuns.data.total_count}):`);
+            for (let run of checkRuns.data.check_runs) {
+              console.log(`- ${run.name}: ${run.conclusion}`);
+            }
+
+            const failedChecks = checkRuns.data.check_runs.filter(run => run.conclusion === 'failure');
+            const pendingChecks = checkRuns.data.check_runs.filter(run => run.status !== 'completed');
+
+            if (failedChecks.length > 0) {
+              core.setFailed('Cannot merge: The main branch has failing checks.');
+            } else if (pendingChecks.length > 0) {
+              core.setFailed('Checks for main branch are pending. Please try again later.');
+            } else {
+              console.log('Main branch is healthy.');
+            }