feat(gha): scope build workflow

.github/workflows/build.yml

@@ -1,12 +1,33 @@
-on: [push, pull_request, workflow_dispatch]
+name: zmk-build-and-release
+
+on:
+  push:
+    paths:
+      - 'config/**'
+      - '.github/workflows/build.yml'
+      - 'build.yaml'
+    branches: [ "mainline" ]
+  pull_request:
+    paths:
+      - 'config/**'
+      - '.github/workflows/build.yml'
+      - 'build.yaml'
+    branches: [ "mainline" ]
+  workflow_dispatch:
 
 jobs:
   build:
-    uses: zmkfirmware/zmk/.github/workflows/build-user-config.yml@main
+    permissions:
+      contents: read
+
+    uses: zmkfirmware/zmk/.github/workflows/build-user-config.yml@v0.3
 
   release:
     needs: build
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
     steps:
       - name: Release artifacts
         uses: softprops/action-gh-release@v2

config/west.yml

@@ -1,11 +1,12 @@
 manifest:
+  defaults:
+    revision: v0.3
   remotes:
     - name: zmkfirmware
       url-base: https://github.com/zmkfirmware
   projects:
     - name: zmk
       remote: zmkfirmware
-      revision: main
       import: app/west.yml
   self:
     path: config

zephyr/module.yml

@@ -0,0 +1,3 @@
+build:
+  settings:
+    board_root: .