🔒️(mail) bump cross-spawn to fix a high severity issue

Bump cross-spawn from 7.0.3 to 7.0.6 in /src/mail
Alert triggered by DependaBot.

src/mail/package-lock.json

@@ -344,8 +344,9 @@
       }
     },
     "node_modules/cross-spawn": {
-      "version": "7.0.3",
-      "license": "MIT",
+      "version": "7.0.6",
+      "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.6.tgz",
+      "integrity": "sha512-uV2QOWP2nWzsy2aMp8aRibhi9dlzF5Hgh5SHaB9OiTGEyDTiJJyx0uy51QXdyWbtAHNua4XJzUKca3OzKUd3vA==",
       "dependencies": {
         "path-key": "^3.1.0",
         "shebang-command": "^2.0.0",