fix: upgrade @apollographql/graphql-playground-html from 1.6.28 to 1.6.29

Snyk has created this PR to upgrade @apollographql/graphql-playground-html from 1.6.28 to 1.6.29.

See this package in npm:
https://www.npmjs.com/package/@apollographql/graphql-playground-html

See this project in Snyk:
https://app.snyk.io/org/acinader/project/8c1a9edb-c8f5-4dc1-b221-4d6030a323eb?utm_source=github&utm_medium=upgrade-pr

Author: snyk-bot

package-lock.json

@@ -19,7 +19,7 @@
   ],
   "license": "BSD-3-Clause",
   "dependencies": {
-    "@apollographql/graphql-playground-html": "1.6.28",
+    "@apollographql/graphql-playground-html": "1.6.29",
     "@graphql-tools/links": "6.2.5",
     "@graphql-tools/stitch": "6.2.4",
     "@graphql-tools/utils": "6.2.4",