fix: upgrade node-fetch from 2.6.1 to 2.6.7

Snyk has created this PR to upgrade node-fetch from 2.6.1 to 2.6.7.

See this package in npm:
https://www.npmjs.com/package/node-fetch

See this project in Snyk:
https://app.snyk.io/org/postman/project/a9d4dce7-380d-43fb-af50-eb18c793de24?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

codegens/js-fetch/package.json

@@ -29,7 +29,7 @@
   "dependencies": {},
   "devDependencies": {
     "form-data": "2.5.1",
-    "node-fetch": "2.6.1"
+    "node-fetch": "2.6.7"
   },
   "engines": {
     "node": ">=8"