Revert "[CI] Simplify uv setup in workflow"

This reverts commit 77ffc43.

Author: Ubospica

.github/workflows/ci_test.yml

@@ -71,8 +71,12 @@ jobs:
         with:
           fetch-depth: 0
           fetch-tags: true
-      - name: Set up uv
-        uses: astral-sh/setup-uv@5a095e7a2014a4212f075830d4f7277575a9d098  # v7.3.1
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.13"
+      - name: Install uv
+        run: python -m pip install uv
       - name: Set up Python environment
         run: uv sync --group dev --no-install-project
       - name: Run pre-commit
@@ -88,10 +92,12 @@ jobs:
           submodules: recursive
           fetch-depth: 0
           fetch-tags: true
-      - name: Set up uv
-        uses: astral-sh/setup-uv@5a095e7a2014a4212f075830d4f7277575a9d098  # v7.3.1
+      - name: Set up Python
+        uses: actions/setup-python@v6
         with:
-          python-version: 3.13
+          python-version: "3.13"
+      - name: Install uv
+        run: python -m pip install uv
       - uses: ./.github/actions/detect-env-vars
         id: env_vars
       - name: Run clang-tidy
@@ -111,10 +117,12 @@ jobs:
           submodules: recursive
           fetch-depth: 0
           fetch-tags: true
-      - name: Set up uv
-        uses: astral-sh/setup-uv@5a095e7a2014a4212f075830d4f7277575a9d098  # v7.3.1
+      - name: Set up Python
+        uses: actions/setup-python@v6
         with:
-          python-version: 3.13
+          python-version: "3.13"
+      - name: Install uv
+        run: python -m pip install uv
       - name: Generate docs
         run: |
           sudo apt install doxygen
@@ -183,15 +191,17 @@ jobs:
 
       # Run Python tests
       - name: Setup Python ${{ matrix.python_version }}
-        uses: astral-sh/setup-uv@5a095e7a2014a4212f075830d4f7277575a9d098  # v7.3.1
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python_version }}
-          activate-environment: true
+          allow-prereleases: true
+      - name: Install uv
+        run: python -m pip install uv
       - name: Build and install python package
         env:
           CMAKE_BUILD_PARALLEL_LEVEL: ${{ steps.env_vars.outputs.cpu_count }}
         run: |
-          uv pip install --reinstall --verbose --group test -e .
+          uv pip install --system --reinstall --verbose --group test -e .
       - name: Run python tests
         if: ${{ matrix.os != 'windows-latest' }}
         run: |