CI: Add runner workflow to call other workflows

.github/workflows/runner.yml

@@ -0,0 +1,21 @@
+name: 🔗 GHA
+on: [push, pull_request, merge_group]
+
+concurrency:
+  group: ci-${{ github.actor }}-${{ github.head_ref || github.run_number }}-${{ github.ref }}-runner
+  cancel-in-progress: true
+
+jobs:
+  # First stage: Only static checks, fast and prevent expensive builds from running.
+
+  static-checks:
+    if: '!vars.DISABLE_GODOT_CI'
+    name: 📊 Static Checks
+    uses: ./.github/workflows/static_checks.yml
+
+  # Second stage: Run all the builds and some of the tests.
+
+  ci:
+    name: 🛠️ Continuous Integration
+    needs: static-checks
+    uses: ./.github/workflows/ci.yml