Separate code coverage CI pipeline

.github/workflows/build_test.yml

@@ -36,12 +36,4 @@ jobs:
       run: cargo build --verbose --release -F apu_blargg
     - name: Run tests
       run: cargo test --verbose
-    - name: Generate code coverage
-      run: cargo llvm-cov --workspace --codecov --output-path codecov.json
-    - name: Upload coverage to Codecov
-      uses: codecov/codecov-action@v3
-      with:
-        token: ${{ secrets.CODECOV_TOKEN }}
-        files: codecov.json
-        fail_ci_if_error: true
 

.github/workflows/coverage.yml

@@ -0,0 +1,37 @@
+name: Test coverage
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Update package repos
+      run: sudo apt-get -y update
+    - name: Install prerequisites
+      run: sudo apt-get -y install libsdl2-dev
+    - name: Install cargo-llvm-cov
+      uses: taiki-e/install-action@cargo-llvm-cov
+    - name: Fetch submodules
+      run: git submodule update --init --recursive
+    - name: Checkout siena_tests
+      run: git clone --recurse-submodules https://github.com/twvd/siena_tests.git ../siena_tests
+    - name: Generate code coverage
+      run: cargo llvm-cov --workspace --codecov --output-path codecov.json
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v3
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}
+        files: codecov.json
+        fail_ci_if_error: true
+