Bump mypy from 1.18.2 to 1.19.0 in /demos

Bumps [mypy](https://github.com/python/mypy) from 1.18.2 to 1.19.0.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.18.2...v1.19.0)

---
updated-dependencies:
- dependency-name: mypy
  dependency-version: 1.19.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

demos/graphql-demo/requirements-dev.txt

@@ -10,7 +10,7 @@ graphql-ws==0.4.4
 psycopg2-binary==2.9.11
 redis==7.1.0
 
-mypy==1.18.2
+mypy==1.19.0
 flake8==7.3.0
 pytest==8.4.2
 pytest-cov==7.0.0

demos/moderator/requirements-dev.txt

@@ -11,7 +11,7 @@ flake8==7.3.0
 flake8-bugbear==24.12.12
 flake8-quotes==3.4.0
 ipdb==0.13.13
-mypy==1.18.2
+mypy==1.19.0
 pytest==8.4.2
 pytest-aiohttp==1.1.0
 pytest-asyncio==0.26.0