chore: Regenerate openapi spec v1.4.0 (#724)

Author: zeljkoX

openapi.json

@@ -12,7 +12,7 @@
       "name": "AGPL-3.0 license",
       "url": "https://github.com/OpenZeppelin/openzeppelin-relayer/blob/main/LICENSE"
     },
-    "version": "1.3.0"
+    "version": "1.4.0"
   },
   "paths": {
     "/api/v1/health": {