feat(typescript-urql-graphcache): mark @urql/exchange-graphcache v6 compatible

Resolves #342

Author: dargmuesli

.changeset/dull-laws-sneeze.md

@@ -0,0 +1,5 @@
+---
+'@graphql-codegen/typescript-urql-graphcache': minor
+---
+
+mark typescript-urql-graphcache as @urql/exchange-graphcache v6 compatible

packages/plugins/typescript/urql-graphcache/package.json

@@ -37,7 +37,7 @@
     "test": "jest --no-watchman --config ../../../../jest.config.js"
   },
   "peerDependencies": {
-    "@urql/exchange-graphcache": "^4.1.1 || ^5.0.0",
+    "@urql/exchange-graphcache": "^4.1.1 || ^5.0.0 || ^6.0.0",
     "graphql": "^0.8.0 || ^0.9.0 || ^0.10.0 || ^0.11.0 || ^0.12.0 || ^0.13.0 || ^14.0.0 || ^15.0.0 || ^16.0.0",
     "graphql-tag": "^2.0.0"
   },