fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-NODEMAILER-13378253

Author: snyk-bot

package.json

@@ -40,7 +40,7 @@
     "mongo-sanitize": "^1.1.0",
     "mongoose": "^5.10.3",
     "morgan": "^1.10.0",
-    "nodemailer": "^6.4.17",
+    "nodemailer": "^7.0.7",
     "uuid": "^8.3.2",
     "winston": "^3.3.3"
   }