perf: increase test parallelization to 8 groups and remove redundant cache

.github/workflows/tests.yml

@@ -18,7 +18,7 @@ jobs:
       fail-fast: true
       matrix:
         python-version: ['3.10', '3.11', '3.12', '3.13']
-        group: [1, 2, 3, 4]
+        group: [1, 2, 3, 4, 5, 6, 7, 8]
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -34,26 +34,16 @@ jobs:
       - name: Set up Python ${{ matrix.python-version }}
         run: uv python install ${{ matrix.python-version }}
 
-      - name: Cache Python packages
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cache/uv
-            ~/.local/share/uv
-          key: ${{ runner.os }}-uv-${{ matrix.python-version }}-${{ hashFiles('**/pyproject.toml', '**/uv.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-uv-${{ matrix.python-version }}-
-
       - name: Install the project
         run: uv sync --dev --all-extras
 
-      - name: Run tests (group ${{ matrix.group }} of 4)
+      - name: Run tests (group ${{ matrix.group }} of 8)
         run: |
           uv run pytest \
             --block-network \
             --timeout=60 \
             -vv \
-            --splits 4 \
+            --splits 8 \
             --group ${{ matrix.group }} \
             --durations=10 \
             -n auto \