ci: remove benchmark job from CI workflow

Too heavy for CI (~2h per run). Benchmarks can be run locally with:
  pytest -m benchmark --bench-scale=small --bench-report=results.json

.github/workflows/ci.yml

@@ -20,22 +20,6 @@ jobs:
       - run: pip install -e ".[dev]"
       - run: python -m pytest tests/ -v --ignore=tests/benchmarks
 
-  benchmark:
-    runs-on: ubuntu-latest
-    if: github.event_name == 'pull_request'
-    steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-python@v6
-        with:
-          python-version: "3.11"
-      - run: pip install -e ".[dev]"
-      - run: python -m pytest tests/benchmarks/ -v -m "benchmark and not stress and not slow" --bench-scale=small --bench-report=bench-results.json
-      - uses: actions/upload-artifact@v6
-        if: always()
-        with:
-          name: benchmark-results
-          path: bench-results.json
-
   lint:
     runs-on: ubuntu-latest
     steps: