multi-arch-test-build: run it only after the Formality check succeeds

Most of the time, when people contribute to the repository for the first time
 (or after a longer break), the multi-arch-test-build passes, but the
formality check fails and requires the contributor to make some changes.

This creates unnecessary load on the CI/CD, since the multi-arch-test-build
runs again even though it already passed, while other PRs are waiting for a runner.
Hopefully, this change will help decrease the waiting time.

Proposed changes:

- Run the formality check first, and only trigger the package tests afterwards.
This can be done using needs: https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#jobsjob_idneeds

- Merge formal.yml into multi-arch-test-build.yml so that needs can be used.

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>

.github/workflows/formal.yml

@@ -1,12 +0,0 @@
-name: Test Formalities
-
-on:
-  pull_request:
-
-permissions:
-  contents: read
-
-jobs:
-  build:
-    name: Test Formalities
-    uses: openwrt/actions-shared-workflows/.github/workflows/formal.yml@main

.github/workflows/multi-arch-test-build.yml

@@ -1,9 +1,14 @@
-name: Feeds Package Test Build
+name: Test and Build
 
 on:
   pull_request:
 
 jobs:
+  formalities:
+    name: Test Formalities
+    uses: openwrt/actions-shared-workflows/.github/workflows/formal.yml@main
+
   build:
     name: Feeds Package Test Build
+    needs: formalities
     uses: openwrt/actions-shared-workflows/.github/workflows/multi-arch-test-build.yml@main