ci: switch to lavapipe

Author: Firestar99

.github/workflows/ci.yaml

@@ -163,10 +163,7 @@ jobs:
           install_runtime: true
           cache: true
           stripdown: true
-
-          # FIXME(eddyb) consider using lavapipe instead, or even trying both.
-          install_swiftshader: true
-          # install_lavapipe: true
+          install_lavapipe: true
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       - if: ${{ runner.os == 'Windows' }}