Upgrade webpack

We're upgrading the minimum version of webpack from 5.28.0 to 5.62.2
since this version doesn't rely on OpenSSL for its hashing algorithm so
it wouldn't need legacy OpenSSL support when we decide to upgrade to
Node 18.

This allows us to build our extension on Node 18:
https://github.com/github/vscode-codeql/runs/6904100934?check_suite_focus=true

Happily, this also works fine with our current version of Node (16.13.0).

Author: elenatanasoiu