fix: run noir browser tests in series (#6232)

This PR removes `--parallel` from the command running the noir browser
tests because of reports of test servers fighting for the `8080` port.

Co-authored-by: ludamad <adam.domurad@gmail.com>

noir/Earthfile

@@ -168,7 +168,6 @@ packages-test-browser:
     WORKDIR /usr/src/noir/noir-repo
     RUN ./.github/scripts/playwright-install.sh
     RUN yarn workspaces foreach \
-      --parallel \
       --verbose \
       --include integration-tests \
       --include @noir-lang/noir_wasm \