Just give up and do an array membership check

.github/workflows/lint-and-test.yaml

@@ -27,7 +27,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: [3.8, 3.9, "3.10", 3.11, 3.12, 3.13]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
     steps:
       - uses: actions/checkout@v4
       - name: Install uv
@@ -53,7 +53,7 @@ jobs:
           uv run --no-sync -- python -c "import nanobind_example; assert nanobind_example.add(1, 2) == 3"
         working-directory: ${{ github.workspace }}/nanobind_example
       - name: Check ${{ matrix.os }} CPython>=3.12 wheels for stable ABI violations
-        if: matrix.python-version >= 3.12
+        if: ${{ contains(fromJSON('["3.12", "3.13"]'), matrix.python-version) }}
         run: |
           uv pip install abi3audit
           uv build --wheel