Support Python 3.15

[ru551n]

Adds support for Python 3.15, released on 9 October 2026.

Changes

• Prebuilt Windows DLL: python_bridge_dlls.yml also builds vunit_python_bridge-cp315-win_amd64.dll, so NVC and GHDL work with 3.15 on Windows without a C compiler. The checks of the built DLLs and of the wheel content (python_bridge.yml, publish.yml) now expect six DLLs. Without that, the release would fail on the extra DLL.

• CI: 3.15 is tested next to 3.14:

  • on Linux and macOS, every job that used 3.14, apart from the canaries, which stay on 3.14;
  • on Windows;
  • in the wheel tests on Linux, macOS and Windows.

  That's 11 more jobs.

• Docs and release notes: the user guide lists 3.15 among the Pythons CI tests on Windows, and the release notes add a line.

The bridge itself needed no change.

Tests

With python-build-standalone's CPython 3.15.0 (shared library, standard GIL build), NumPy 2.5.4 and VUnit 5.0.0.dev14:

• Unit tests: 101 passed.
• VHDL tests from the repository root, on NVC 1.23-devel and on GHDL 7.0.0-dev mcode: 109 of 109, and tests/file_base 7 of 7 with the base directory set by the run script and 7 of 7 with it set by the environment variable.
• The C sources of the bridge compile against the 3.15 headers with -Wall -Wextra and no warnings, so no deprecated C API is used.

The Windows DLL build with MSVC and the macOS jobs are tested by this PR's CI.

🤖 Generated with Claude Code