[ci] Only install chromium for flight fixtures (facebook#32275)

I noticed we only use chromium in fixtures/flight, so let's specifically
only install that browser in ci.

Author: poteto

.github/workflows/runtime_build_and_test.yml

@@ -476,9 +476,7 @@ jobs:
           fi
       - name: Playwright install deps
         working-directory: fixtures/flight
-        run: |
-          npx playwright install
-          sudo npx playwright install-deps
+        run: npx playwright install --with-deps chromium
       - name: Run tests
         working-directory: fixtures/flight
         run: yarn test