build(deps): bump slack-sdk from 3.43.0 to 3.44.0 in /block-kit

Bumps [slack-sdk](https://github.com/slackapi/python-slack-sdk) from 3.43.0 to 3.44.0.
- [Release notes](https://github.com/slackapi/python-slack-sdk/releases)
- [Commits](slackapi/python-slack-sdk@v3.43.0...v3.44.0)

---
updated-dependencies:
- dependency-name: slack-sdk
  dependency-version: 3.44.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

block-kit/requirements.txt

@@ -1,4 +1,4 @@
 mypy==2.3.1
 pytest==9.1.1
 ruff==0.16.4
-slack_sdk==3.43.0
+slack_sdk==3.44.0