CI: drop the launcher bridge test (the bridge was removed)

tools/test_launcher_bridge.py tested crates/coa-core/src/launcher_bridge.py,
which the Rust launcher replaced; check.yml and release.yml still ran it, so
the release build failed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/check.yml

@@ -26,5 +26,4 @@ jobs:
       - run: node tools/check-i18n.mjs
       - run: npm run build
       - run: node --experimental-strip-types --test tools/*.test.mjs
-      - run: python -B -m unittest discover -s tools -p test_launcher_bridge.py
       - run: cargo test --workspace --locked

.github/workflows/release.yml

@@ -74,7 +74,6 @@ jobs:
       - name: Tests
         run: cargo test --workspace --locked -- --test-threads=1
       - run: node --experimental-strip-types --test tools/*.test.mjs
-      - run: python -B -m unittest discover -s tools -p test_launcher_bridge.py
       - name: Build and sign (publish only when requested)
         id: tauri
         uses: tauri-apps/tauri-action@v0