ci: add GCC build workflow

Author: a5021

.github/workflows/build.yml

@@ -0,0 +1,21 @@
+name: Build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install ARM GCC toolchain
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gcc-arm-none-eabi
+
+      - name: Build
+        run: make