fix(deps): update dependency mailgun.js to v11 (#82)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

src/server/package.json

@@ -21,7 +21,7 @@
         "fastify": "^5.2.0",
         "fastify-plugin": "^5.0.1",
         "form-data": "^4.0.1",
-        "mailgun.js": "^10.3.0"
+        "mailgun.js": "^11.0.0"
     },
     "devDependencies": {
         "@eslint/js": "^9.17.0",