chore(deps): bump node-fetch from 2.5.0 to 2.6.0

Bumps [node-fetch](https://github.com/bitinn/node-fetch) from 2.5.0 to 2.6.0.
- [Release notes](https://github.com/bitinn/node-fetch/releases)
- [Changelog](https://github.com/bitinn/node-fetch/blob/master/CHANGELOG.md)
- [Commits](https://github.com/bitinn/node-fetch/compare/v2.5.0...v2.6.0)

web3.js/package-lock.json

@@ -12911,9 +12911,9 @@
       }
     },
     "node-fetch": {
-      "version": "2.5.0",
-      "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.5.0.tgz",
-      "integrity": "sha512-YuZKluhWGJwCcUu4RlZstdAxr8bFfOVHakc1mplwHkk8J+tqM1Y5yraYvIUpeX8aY7+crCwiELJq7Vl0o0LWXw=="
+      "version": "2.6.0",
+      "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.6.0.tgz",
+      "integrity": "sha512-8dG4H5ujfvFiqDmVu9fQ5bOHUC15JMjMY/Zumv26oOvvVJjM67KF8koCWIabKQ1GJIa9r2mMZscBq/TbdOcmNA=="
     },
     "node-int64": {
       "version": "0.4.0",