deps(build): update esbuild-loader to 4.3.0 (#6622)

## Problem
- we have a couple moderate vulnerabilities due to an old version of
esbuild-loader

## Solution
- update esbuild-loader + other npm packages that have vulnerabilities

## Notes
- In the [3.0.0 esbuild-loader
version](https://github.com/privatenumber/esbuild-loader/releases/tag/v3.0.0)
ESBuildMinifyPlugin was re-named to EsbuildPlugin, it still does the
minification by default though

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: jpinkney-aws