ci: bump slackapi/slack-github-action from 1.25.0 to 1.26.0

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

---
updated-dependencies:
- dependency-name: slackapi/slack-github-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

.github/workflows/ci.yml

@@ -61,7 +61,7 @@ jobs:
         env:
           FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
       - if: failure()
-        uses: slackapi/slack-github-action@v1.25.0
+        uses: slackapi/slack-github-action@v1.26.0
         with:
           channel-id: filecoin-station-incidents
           payload: |