Keep the Python 3.14 patchlevel pin up to date

[potiuk]

scripts/ci/prek/upgrade_important_versions.py kept its own hard-coded list of the Python major/minor
versions it maintains:

ALL_PYTHON_MAJOR_MINOR_VERSIONS = ["3.10", "3.11", "3.12", "3.13"]

while global_constants.py has had all five since Python 3.14 was added in #63520 (March 2026). That PR
added "3.14": "3.14.3" to ALL_PYTHON_VERSION_TO_PATCHLEVEL_VERSION but did not touch this list, so the
bumper has never once looked at 3.14 — the pin has been frozen at 3.14.3 for roughly six months while
3.10 through 3.13 kept moving.

The list now comes from global_constants.py through the existing
read_allowed_python_major_minor_versions() helper, which the same module already uses for
DEFAULT_PYTHON_MAJOR_MINOR_VERSION_FOR_IMAGES — so the duplication had no reason to exist, and the next
Python version added to Airflow is picked up automatically rather than needing a second edit nobody
remembers to make.

The stale pin is corrected in the same change: 3.14.3 → 3.14.7, which is the latest 3.14 on
python.org.

Verification

• read_allowed_python_major_minor_versions() returns ['3.10', '3.11', '3.12', '3.13', '3.14'].
• ruff check clean on both files.

---

Was generative AI tooling used to co-author this PR?

• Yes — Claude Code (Opus 5)

Generated-by: Claude Code (Opus 5) following the guidelines

🤖 Generated with Claude Code

https://claude.ai/code/session_01DcRW9x8n7Jor7ftsKFxQHD

[github-actions]

Backport failed to create: v3-3-test. View the failure log Run details

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
❌	v3-3-test

You can attempt to backport this manually by running:

cherry_picker 7fa3c6b v3-3-test

This should apply the commit to the v3-3-test branch and leave the commit in conflict state marking
the files that need manual conflict resolution.

After you have resolved the conflicts, you can continue the backport process by running:

cherry_picker --continue

If you don't have cherry-picker installed, see the installation guide.