chore: bump cross-env from 7.0.2 to 7.0.3 in /web3.js (#13915)

Bumps [cross-env](https://github.com/kentcdodds/cross-env) from 7.0.2 to 7.0.3.
- [Release notes](https://github.com/kentcdodds/cross-env/releases)
- [Changelog](https://github.com/kentcdodds/cross-env/blob/master/CHANGELOG.md)
- [Commits](kentcdodds/cross-env@v7.0.2...v7.0.3)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

web3.js/package.json

@@ -107,7 +107,7 @@
     "babel-eslint": "10.1.0",
     "babel-plugin-module-resolver": "4.0.0",
     "codecov": "^3.0.4",
-    "cross-env": "7.0.2",
+    "cross-env": "7.0.3",
     "elfy": "^1.0.0",
     "enzyme": "3.11.0",
     "esdoc": "^1.1.0",