Bump @slack/web-api from 7.3.4 to 7.4.0 (#135)

Bumps [@slack/web-api](https://github.com/slackapi/node-slack-sdk) from 7.3.4 to 7.4.0.
- [Release notes](https://github.com/slackapi/node-slack-sdk/releases)
- [Commits](https://github.com/slackapi/node-slack-sdk/compare/@slack/[email protected]...@slack/[email protected])

---
updated-dependencies:
- dependency-name: "@slack/web-api"
  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>

package.json

@@ -10,7 +10,7 @@
   },
   "dependencies": {
     "@probot/adapter-aws-lambda-serverless": "^3.0.4",
-    "@slack/web-api": "^7.3.4",
+    "@slack/web-api": "^7.4.0",
     "probot": "^12.3.3"
   },
   "repository": "github:emergency-pull-request-probot-app",