fix: upgrade mailparser from 3.7.5 to 3.9.0

Snyk has created this PR to upgrade mailparser from 3.7.5 to 3.9.0.

See this package in npm:
mailparser

See this project in Snyk:
https://app.snyk.io/org/oneuptime-RsC2nshvQ2Vnr35jHvMnMP/project/c3622982-05c8-495c-809c-20f301c75f92?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -9,7 +9,7 @@
         "eslint-plugin-unused-imports": "^4.3.0",
         "globals": "^15.15.0",
         "jest": "^30.2.0",
-        "mailparser": "^3.7.5",
+        "mailparser": "^3.9.0",
         "ts-node": "^10.9.2",
         "typeorm": "^0.3.27"
     },