⬆️ Update GraphQL to v15.7.2

New major version 16 is released few days ago, but
other dependencies aren't ready for the upgrade

By the words of a main maintainer of type-graphql package
that we use, support for GraphQL version 16 "won't happen soon,
as all the other GraphQL ecosystem tools need to support v16 too."
MichalLytek/type-graphql#1100

package.json

@@ -17,7 +17,7 @@
   "dependencies": {
     "apollo-server-hapi": "^2.25.0",
     "class-validator": "^0.13.1",
-    "graphql": "^15.5.0",
+    "graphql": "^15.7.2",
     "knex": "^0.95.6",
     "pg": "^8.6.0",
     "reflect-metadata": "^0.1.13",

yarn.lock

@@ -1799,10 +1799,10 @@ graphql-tools@^4.0.8:
     iterall "^1.1.3"
     uuid "^3.1.0"
 
-graphql@^15.5.0:
-  version "15.5.0"
-  resolved "https://registry.yarnpkg.com/graphql/-/graphql-15.5.0.tgz#39d19494dbe69d1ea719915b578bf920344a69d5"
-  integrity sha512-OmaM7y0kaK31NKG31q4YbD2beNYa6jBBKtMFT6gLYJljHLJr42IqJ8KX08u3Li/0ifzTU5HjmoOOrwa5BRLeDA==
+graphql@^15.7.2:
+  version "15.7.2"
+  resolved "https://registry.yarnpkg.com/graphql/-/graphql-15.7.2.tgz#85ab0eeb83722977151b3feb4d631b5f2ab287ef"
+  integrity sha512-AnnKk7hFQFmU/2I9YSQf3xw44ctnSFCfp3zE0N6W174gqe9fWG/2rKaKxROK7CcI3XtERpjEKFqts8o319Kf7A==
 
 has-bigints@^1.0.1:
   version "1.0.1"