ci: also test --target-env vulkan1.2.

Author: eddyb

.github/workflows/ci.yaml

@@ -72,7 +72,7 @@ jobs:
 
       - name: compiletest
         if: ${{ matrix.target != 'aarch64-linux-android' }}
-        run: cargo run -p compiletests --release --no-default-features --features "use-installed-tools" -- --target-env vulkan1.1,spv1.3
+        run: cargo run -p compiletests --release --no-default-features --features "use-installed-tools" -- --target-env vulkan1.1,vulkan1.2,spv1.3
 
       # Examples
       - name: cargo check examples