Force only-managed for all uv invokations

Author: urob

.github/workflows/wheels.yml

@@ -103,7 +103,7 @@ jobs:
 
       - name: Prepare environment
         run: |
-          echo "UV_PYTHON=${{ matrix.python }}" >>$GITHUB_ENV
+          # Need this since pyproject.toml doesn't apply to $SRC_DIR.
           echo "UV_PYTHON_PREFERENCE=only-managed" >>$GITHUB_ENV
 
           case "${{ runner.os }}" in
@@ -122,6 +122,7 @@ jobs:
       - name: Install uv
         uses: astral-sh/setup-uv@3259c6206f993105e3a61b142c2d97bf4b9ef83d # v7.1.0
         with:
+          python-version: ${{ matrix.python }}
           version-file: "pyproject.toml"
           enable-cache: false
 

pyproject.toml

@@ -45,4 +45,5 @@ skip-magic-trailing-comma = false
 
 [tool.uv]
 required-version = "~=0.9"
+python-preference = "only-managed"
 package = false