Merge pull request #24 from mrpippy/main

CI improvements (use checkout v4, add workflow_dispatch trigger)

.github/workflows/main.yml

@@ -5,6 +5,7 @@ on:
     branches: [ main ]
   pull_request:
     branches: [ main ]
+  workflow_dispatch:
 
 jobs:
   build:
@@ -111,7 +112,7 @@ jobs:
     runs-on: ${{ matrix.config.platform }}
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up build environment
       run: docker run --rm --privileged multiarch/qemu-user-static:register --reset
       if: matrix.config.qemu == true