[Dependabot]: Update mypy requirement from ~=1.13 to ~=1.15

Updates the requirements on [mypy](https://github.com/python/mypy) to permit the latest version.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.13.0...v1.15.0)

---
updated-dependencies:
- dependency-name: mypy
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

tests/requirements.txt

@@ -8,6 +8,6 @@ pytest ~= 8.3
 pytest-cov ~= 6.0
 
 # Static Type Checking
-mypy ~= 1.13
+mypy ~= 1.15
 typing_extensions ~= 4.12
 lxml ~= 5.3