build(deps): bump validator from 13.12.0 to 13.15.0 in /backend (#8297)

Bumps [validator](https://github.com/validatorjs/validator.js) from 13.12.0 to 13.15.0.
- [Release notes](https://github.com/validatorjs/validator.js/releases)
- [Changelog](https://github.com/validatorjs/validator.js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/validatorjs/validator.js/compare/13.12.0...13.15.0)

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

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

backend/package.json

@@ -91,7 +91,7 @@
     "subscriptions-transport-ws": "^0.9.19",
     "trunc-html": "~1.1.2",
     "uuid": "~9.0.1",
-    "validator": "^13.12.0",
+    "validator": "^13.15.0",
     "xregexp": "^5.1.2"
   },
   "devDependencies": {

backend/yarn.lock

@@ -9777,10 +9777,10 @@ v8flags@^3.1.1:
   dependencies:
     homedir-polyfill "^1.0.1"
 
-validator@^13.12.0:
-  version "13.12.0"
-  resolved "https://registry.yarnpkg.com/validator/-/validator-13.12.0.tgz#7d78e76ba85504da3fee4fd1922b385914d4b35f"
-  integrity sha512-c1Q0mCiPlgdTVVVIJIrBuxNicYE+t/7oKeI9MWLj3fh/uq2Pxh/3eeWbVZ4OcGW1TUf53At0njHw5SMdA3tmMg==
+validator@^13.15.0:
+  version "13.15.0"
+  resolved "https://registry.yarnpkg.com/validator/-/validator-13.15.0.tgz#2dc7ce057e7513a55585109eec29b2c8e8c1aefd"
+  integrity sha512-36B2ryl4+oL5QxZ3AzD0t5SsMNGvTtQHpjgFO5tbNxfXbMFkY822ktCDe1MnlqV3301QQI9SLHDNJokDI+Z9pA==
 
 vary@^1, vary@~1.1.2:
   version "1.1.2"