Remove support for Python 3.7 in build_nnef.yml

Not supported in latest cibuildwheel tools

Author: gyenesvi

.github/workflows/build_nnef.yml

@@ -28,7 +28,7 @@ jobs:
           output-dir: dist/
           config-file: nnef-pyproject/pyproject.toml
         env:
-          CIBW_BUILD: "cp37-* cp38-* cp39-* cp310-* cp311-* cp312-* cp313-* cp314-*"
+          CIBW_BUILD: "cp38-* cp39-* cp310-* cp311-* cp312-* cp313-* cp314-*"
 
       - uses: actions/upload-artifact@v4
         with: