chore: simplify Python version handling in configuration

- Updated mise.toml to directly specify the Python version instead of using the CI environment variable.
- Added MISE_PYTHON_VERSION to the GitHub Actions workflow for performance optimization, allowing uv to reuse the installed Python.

Author: timonrieger

.github/workflows/cd.yml

@@ -28,6 +28,9 @@ jobs:
       pull-requests: write
     env:
       UV_PYTHON: ${{ matrix.python-version }}
+      # technically not needed, since uv will read UV_PYTHON from the environment,
+      # but this way uv can reuse mise's installed Python (performance)
+      MISE_PYTHON_VERSION: ${{ matrix.python-version }}
 
     strategy:
       fail-fast: false

mise.toml

@@ -1,6 +1,5 @@
 [tools]
-# reuse UV_PYTHON from the CI environment to avoid installing two versions of Python (performance)
-python = "{{ get_env(name='UV_PYTHON', default='3.14.2') }}"
+python = "3.14.2"
 uv = "0.9.21"
 
 # https://mise.jdx.dev/mise-cookbook/python.html#mise-uv