build(deps): bump slackapi/slack-github-action from 3 to 4 (#721)

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 3 to 4.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Changelog](https://github.com/slackapi/slack-github-action/blob/main/CHANGELOG.md)
- [Commits](slackapi/slack-github-action@v3...v4)

---
updated-dependencies:
- dependency-name: slackapi/slack-github-action
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/e2e-test.yml

@@ -253,7 +253,7 @@ jobs:
     steps:
       - name: Notify Slack
         id: main_message
-        uses: slackapi/slack-github-action@v3
+        uses: slackapi/slack-github-action@v4
         with:
           method: chat.postMessage
           token: ${{ secrets.SLACK_BOT_TOKEN }}
@@ -285,7 +285,7 @@ jobs:
 
       - name: Test summary thread
         if: success()
-        uses: slackapi/slack-github-action@v3
+        uses: slackapi/slack-github-action@v4
         with:
           method: chat.postMessage
           token: ${{ secrets.SLACK_BOT_TOKEN }}

.github/workflows/nightly-smoke-tests.yml

@@ -45,7 +45,7 @@ jobs:
 
       - name: Notify Slack
         if: always() && github.repository == 'linode/linode_api4-python'
-        uses: slackapi/slack-github-action@v3
+        uses: slackapi/slack-github-action@v4
         with:
           method: chat.postMessage
           token: ${{ secrets.SLACK_BOT_TOKEN }}

.github/workflows/release-notify-slack.yml

@@ -11,7 +11,7 @@ jobs:
     steps:
       - name: Notify Slack - Main Message
         id: main_message
-        uses: slackapi/slack-github-action@v3
+        uses: slackapi/slack-github-action@v4
         with:
           method: chat.postMessage
           token: ${{ secrets.SLACK_BOT_TOKEN }}