build: use GraphQL URL from env in gql-codegen (#2749)

Co-authored-by: Andrew Bastin <andrewbastin.k@gmail.com>

packages/hoppscotch-app/gql-codegen.yml

@@ -1,5 +1,6 @@
 overwrite: true
-schema: https://api.hoppscotch.io/graphql
+schema:
+  - ${VITE_BACKEND_GQL_URL}
 generates:
   src/helpers/backend/graphql.ts:
     documents: "src/**/*.graphql"

packages/hoppscotch-app/package.json

@@ -5,14 +5,14 @@
   "scripts": {
     "dev": "pnpm exec npm-run-all -p -l dev:*",
     "dev:vite": "vite",
-    "dev:gql-codegen": "graphql-codegen --config gql-codegen.yml --watch",
+    "dev:gql-codegen": "graphql-codegen --require dotenv/config --config gql-codegen.yml --watch",
     "build": "node --max_old_space_size=16384 ./node_modules/vite/bin/vite.js build",
     "lint": "eslint src --ext .ts,.js,.vue --ignore-path .gitignore .",
     "prod-lint": "cross-env HOPP_LINT_FOR_PROD=true pnpm run lint",
     "lintfix": "eslint --fix src --ext .ts,.js,.vue --ignore-path .gitignore .",
     "generate": "pnpm run build",
     "preview": "vite preview",
-    "gql-codegen": "graphql-codegen --config gql-codegen.yml",
+    "gql-codegen": "graphql-codegen --require dotenv/config --config gql-codegen.yml",
     "postinstall": "pnpm run gql-codegen",
     "do-dev": "pnpm run dev",
     "do-build-prod": "pnpm run build",