Test the feature gates on CI

Author: phil-opp

.github/workflows/ci.yml

@@ -62,6 +62,14 @@ jobs:
       - name: Run integration tests
         run: cargo test
 
+      # test feature gates (only on one OS is enough)
+      - name: Test with only UEFI feature
+        if: runner.os == 'Linux'
+        run: cargo test --no-default-features --features uefi
+      - name: Test with only BIOS feature
+        if: runner.os == 'Linux'
+        run: cargo test --no-default-features --features bios
+
   fmt:
     name: Check Formatting
     runs-on: ubuntu-latest