Bump chardet from 7.4.2 to 7.4.3 in /demos

Bumps [chardet](https://github.com/chardet/chardet) from 7.4.2 to 7.4.3.
- [Release notes](https://github.com/chardet/chardet/releases)
- [Changelog](https://github.com/chardet/chardet/blob/main/docs/changelog.rst)
- [Commits](chardet/chardet@7.4.2...7.4.3)

---
updated-dependencies:
- dependency-name: chardet
  dependency-version: 7.4.3
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

demos/moderator_bot/requirements-dev.txt

@@ -4,7 +4,7 @@ async-timeout==5.0.1
 atomicwrites==1.4.1
 attrs==26.1.0
 certifi==2026.1.4
-chardet==7.4.2
+chardet==7.4.3
 idna==3.11
 importlib-metadata==0.23 ; python_version < '3.8'
 joblib==1.5.3