build(deps): bump nodemailer from 6.8.0 to 6.9.1 (#153)

Bumps [nodemailer](https://github.com/nodemailer/nodemailer) from 6.8.0 to 6.9.1.
- [Release notes](https://github.com/nodemailer/nodemailer/releases)
- [Changelog](https://github.com/nodemailer/nodemailer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/nodemailer/nodemailer/compare/v6.8.0...v6.9.1)

---
updated-dependencies:
- dependency-name: nodemailer
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

package.json

@@ -4,7 +4,7 @@
   "dependencies": {
     "@actions/core": "^1.2.7",
     "@actions/glob": "^0.4.0",
-    "nodemailer": "^6.7.8",
+    "nodemailer": "^6.9.1",
     "showdown": "^1.9.1"
   }
 }