fix release: remove pyproject.toml, use --no-build-isolation so cython/numpy visible

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ratal

.github/workflows/release-linux.yml

@@ -24,6 +24,7 @@ jobs:
           CIBW_MANYLINUX_X86_64_IMAGE: manylinux2014
           CIBW_MANYLINUX_AARCH64_IMAGE: manylinux2014
           CIBW_BEFORE_BUILD: pip install numpy cython
+          CIBW_BUILD_FRONTEND: "pip; args: --no-build-isolation"
           CIBW_TEST_COMMAND: python -c "import mdfreader"
       - uses: actions/upload-artifact@v4
         with:

.github/workflows/release-macos.yml

@@ -15,6 +15,7 @@ jobs:
           CIBW_BUILD: "cp39-* cp310-* cp311-* cp312-* cp313-*"
           CIBW_ARCHS: x86_64 arm64
           CIBW_BEFORE_BUILD: pip install numpy cython
+          CIBW_BUILD_FRONTEND: "pip; args: --no-build-isolation"
           CIBW_TEST_COMMAND: python -c "import mdfreader"
       - uses: actions/upload-artifact@v4
         with:

.github/workflows/release-windows.yml

@@ -14,6 +14,7 @@ jobs:
         env:
           CIBW_BUILD: "cp39-win_amd64 cp310-win_amd64 cp311-win_amd64 cp312-win_amd64 cp313-win_amd64"
           CIBW_BEFORE_BUILD: pip install numpy cython
+          CIBW_BUILD_FRONTEND: "pip; args: --no-build-isolation"
           CIBW_TEST_COMMAND: python -c "import mdfreader"
       - uses: actions/upload-artifact@v4
         with: