Add Forgejo workflow

.forgejo/workflows/build.yaml

@@ -0,0 +1,16 @@
+name: Build
+on: [push]
+jobs:
+  build:
+    runs-on: debian-12
+    steps:
+      - name: Install dependencies
+        run: apt-get update && apt-get install -y clang gcc-multilib llvm mtools parted udev
+      - name: Install Rustup
+        run: curl https://sh.rustup.rs | sh -s -- -y
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+      - name: Build
+        run: . ~/.bashrc && ./build.sh