fix(ci): ensure proper version in PyPI releases

Fix release workflow to properly resolve version from git tags instead
of defaulting to 0.0.0. The issue occurred because actions/checkout@v4
requires explicit tag fetching, unlike the older v2 used in upstream.

Changes:
- Add ref: ${{ github.ref }} to checkout the exact release tag
- Add fetch-tags: true to explicitly fetch all tags for setuptools_scm

This ensures setuptools_scm can properly determine the version from
git tags (e.g., v1.12.2.4-beta3 → 1.12.2.4b3) instead of falling back
to version 0.0.0.

Related: Previous releases incorrectly published as version 0.0.0

Author: mfranczel

.github/workflows/release.yml

@@ -30,7 +30,9 @@ jobs:
           restore-keys: ${{ runner.os }}-${{ matrix.PYTHON_VERSION }}-pip-
       - uses: actions/checkout@v4
         with:
+          ref: ${{ github.ref }}
           fetch-depth: 0
+          fetch-tags: true
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.PYTHON_VERSION }}