[MNT] add support for python 3.14

[ankitlade12]

[MNT] add support for python 3.14 (#890)

Description

This PR adds official support for Python 3.14 to feature_engine. It updates the test matrix in both tox.ini and CircleCI to ensure the library remains stable and compatible with the latest Python release.

Changes

• Configuration:
  • Added py314 to envlist and created a corresponding [testenv:py314] section in tox.ini.
  • Added a test_feature_engine_py314 job to .circleci/config.yml and integrated it into the test-all and package_and_upload_to_pypi workflows.
• Documentation:
  • Updated docs/whats_new/v_190.rst to include Python 3.14 support under Code Maintenance.
  • Added @ankitlade12 to the project contributors list.

Verification Results

I have verified these changes by running the full unit test suite (1945 tests) on a Python 3.14.0 environment. All tests passed successfully.

I also double-checked both configuration files to ensures that support for older Python versions (3.9 - 3.13) was not affected.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.22%. Comparing base (aa60b23) to head (ae83603).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #892   +/-   ##
=======================================
  Coverage   98.22%   98.22%           
=======================================
  Files         113      113           
  Lines        4842     4842           
  Branches      768      768           
=======================================
  Hits         4756     4756           
  Misses         55       55           
  Partials       31       31           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[solegalli]

Thank you @ankitlade12

This is great. I assume it is ready to merge, shall I go ahead?

I normally update the what's new file shortly before launching the new version of feature-engine, and then I let everyone who has contributed know, so they can check it and once they are happy, we launch. So I removed it from here.

Thanks again!

[ankitlade12]

Thank you @solegalli!

Yes, please go ahead and merge. I understand about the what's new file—thanks for handling that. Happy to see this moving forward!