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](https://github.com/slackapi/slack-github-action/compare/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/continuous-integration-workflow.yml

@@ -243,7 +243,7 @@ jobs:
           ./gradlew createGitHubRelease -PnextVersion=$VERSION -Pbranch=$BRANCH -PcreateRelease=true -PgitHubAccessToken=$TOKEN
       - name: Announce Release on Slack
         id: spring-security-announcing
-        uses: slackapi/slack-github-action@v1.25.0
+        uses: slackapi/slack-github-action@v1.26.0
         with:
           payload: |
             {