Add Python 3.14 to Black

[trjohnson19]

Black has supported Python 3.14 since v25.11.0 (specifically psf/black#4804).

Running the check

node ./cli.js check --schema-name=partial-black.json

returned all successful tests:

===== VALIDATE PRECONDITIONS =====
✔️ Directory structure conforms to expected layout
✔️ catalog.json validates against its schema
✔️ catalog.json has no fields that break guidelines
✔️ catalog.json has no duplicate "fileMatch" values
✔️ catalog.json has no invalid schema URLs
✔️ catalog.json has all local entries that exist in file total
✔️ schema-validation.jsonc validates against its schema
✔️ schema-validation.jsonc has no invalid schema names
✔️ schema-validation.jsonc has no invalid schema URLs
✔️ schema-validation.jsonc has no invalid skiptest[] entries
===== VALIDATE SCHEMAS =====
✔️ Completed "pre-checks"
✔️ Completed "Ajv validation"
===== REPORT =====
Out of 1767 TOTAL schemas:
- 752 (43%) are SchemaStore URLs
- 1015 (57%) are External URLs

Out of 744 TESTED schemas:
- 282 (38%) are validated with Ajv's strict mode
- 537 (72%) have tests
- 138 (19%) have negative tests

Out of 1 TESTED schemas:
- Total  2020-12: 0
- Total  2019-09: 0
- Total draft-07: 1
- Total draft-06: 0
- Total draft-04: 0
- Total draft-03: 0

[github-actions]

Thanks for the PR!

This section of the codebase is owned by @madskristensen and @hyperupcall - if they write a comment saying "LGTM" then it will be merged.

[hyperupcall]

Thanks