PYTHON-5624 - Add Python 3.14 trove classifier

[NoahStapp]

PYTHON-5624

Summary

Add the 3.14 trove classifier to our pyproject.toml.

Changes in this PR

Add the 3.14 trove classifier to our pyproject.toml.

Testing Plan

No additional testing, as this is a pure metadata change within pyproject.toml

Screenshots (optional)

N/A.

Checklist

Checklist for Author

• Did you update the changelog (if necessary)?
• Is the intention of the code captured in relevant tests?
• If there are new TODOs, has a related JIRA ticket been created?

Checklist for Reviewer {@primary_reviewer}

• Does the title of the PR reference a JIRA Ticket?
• Do you fully understand the implementation? (Would you be comfortable explaining how this code works to someone else?)
• Have you checked for spelling & grammar errors?
• Is all relevant documentation (README or docstring) updated?

Focus Areas for Reviewer (optional)

N/A.

[blink1073]

LGTM!