Bump slack-bolt from 1.25.0 to 1.26.0 (#60)

Bumps [slack-bolt](https://github.com/slackapi/bolt-python) from 1.25.0 to 1.26.0.
- [Release notes](https://github.com/slackapi/bolt-python/releases)
- [Commits](slackapi/bolt-python@v1.25.0...v1.26.0)

---
updated-dependencies:
- dependency-name: slack-bolt
  dependency-version: 1.26.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -1,4 +1,4 @@
-slack-bolt==1.25.0
+slack-bolt==1.26.0
 pytest==8.4.2
 flake8==7.3.0
 black==25.9.0