Permit building mkl_fft with Python 3.13

[ndgrigorian]

Add python 3.13 builds to workflows

[Copilot]

Pull Request Overview

This PR enables Python 3.13 support across the project’s packaging and CI workflows.

• Adds Python 3.13 classifier and updates requires-python range in pyproject.toml.
• Documents Python 3.13 support in CHANGELOG.md.
• Extends GitHub Actions matrices to include Python 3.13 in conda and pip builds.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pyproject.toml	Added 3.13 classifier and bumped requires-python to <3.14
CHANGELOG.md	Added [dev] entry for Python 3.13 support
.github/workflows/conda-package.yml	Included Python 3.13 in the conda packaging matrix
.github/workflows/conda-package-cf.yml	Included Python 3.13 and corresponding NumPy versions
.github/workflows/build_pip.yaml	Added Python 3.13 matrix and setuptools install
.github/workflows/build-with-clang.yml	Included Python 3.13 in clang build matrix

Comments suppressed due to low confidence (2)

CHANGELOG.md:7

• Replace the placeholder date 'YYYY-MM-DD' with the actual release or update date to keep the changelog accurate.

## [dev] - YYYY-MM-DD

.github/workflows/conda-package.yml:23

• [nitpick] The Python version list is duplicated across multiple workflow files; consider defining it once (e.g., via a YAML anchor or reusable strategy) to reduce duplication and risk of inconsistency.

        python: ['3.9', '3.10', '3.11', '3.12', '3.13']

[antonwolfy]

LGTM!