build(deps): bump mypy from 1.20.1 to 1.20.2 in /block-kit

Bumps [mypy](https://github.com/python/mypy) from 1.20.1 to 1.20.2.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.20.1...v1.20.2)

---
updated-dependencies:
- dependency-name: mypy
  dependency-version: 1.20.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

block-kit/requirements.txt

@@ -1,4 +1,4 @@
-mypy==1.20.1
+mypy==1.20.2
 pytest==9.0.3
 ruff==0.15.11
 slack_sdk==3.41.0