Bump 8398a7/action-slack from 3.16.2 to 3.18.0

Bumps [8398a7/action-slack](https://github.com/8398a7/action-slack) from 3.16.2 to 3.18.0.
- [Release notes](https://github.com/8398a7/action-slack/releases)
- [Commits](8398a7/action-slack@28ba43a...1750b50)

---
updated-dependencies:
- dependency-name: 8398a7/action-slack
  dependency-version: 3.18.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/actionlint.yml

@@ -37,7 +37,7 @@ jobs:
           bash <(curl -LsS --retry 2 https://raw.githubusercontent.com/rhysd/actionlint/main/scripts/download-actionlint.bash)
           ./actionlint -color
 
-      - uses: 8398a7/action-slack@28ba43ae48961b90635b50953d216767a6bea486 # v3
+      - uses: 8398a7/action-slack@1750b5085f3ec60384090fb7c52965ef822e869e # v3
         with:
           status: ${{ job.status }}
           fields: repo,message,job,pullRequest

.github/workflows/metacheck.yml

@@ -32,7 +32,7 @@ jobs:
 
       - uses: DeNA/unity-meta-check@a2e35e2c0b652031facd143db6f0a438b49de38a # v4
 
-      - uses: 8398a7/action-slack@28ba43ae48961b90635b50953d216767a6bea486 # v3
+      - uses: 8398a7/action-slack@1750b5085f3ec60384090fb7c52965ef822e869e # v3
         with:
           status: ${{ job.status }}
           fields: repo,message,job,pullRequest