feat: esbuild 0.20.x (backport #1251) (#1253)

Upgrades esbuild to ^0.20.0. Please not that according to the support policy, minor version upgrades of esbuild might include breaking changes. See the esbuild release for details: https://github.com/evanw/esbuild/releases/tag/v0.20.0

To stay on a different version of esbuild, see https://github.com/mrgrain/cdk-esbuild?tab=readme-ov-file#tsjs-how-can-i-use-a-different-version-of-esbuild
<hr>This is an automatic backport of pull request #1251 done by [Mergify](https://mergify.com).