Use new language server w/ NoUnusedVariablesRule disabled (#8287)

* Use new language server w/ unused variables check disabled

* changelog

Author: hlshen

firebase-vscode/CHANGELOG.md

@@ -1,5 +1,7 @@
 ## NEXT
 
+- Allow unused variables in GraphQL queries and mutations.
+
 ## 0.14.0
 
 - Updated internal `firebase-tools` dependency to 13.32.0

firebase-vscode/graphql-language-service-5.2.0.tgz

@@ -87,7 +87,7 @@
           "default": "./exportedData",
           "markdownDescription": "%ext.config.emulators.exportPath%"
         },
-        "firebase.emulators.exportOnExit":{
+        "firebase.emulators.exportOnExit": {
           "type": "boolean",
           "default": false,
           "markdownDescription": "%ext.config.emulators.exportOnExit%"