Trace and replace the @esbuild-kit/* transitive dependency (merged into tsx upstream)

[JSONbored]

Context

Split out of #8588 (task 3 of 4). npm install warns:

npm warn deprecated @esbuild-kit/esm-loader@2.6.5: Merged into tsx: https://tsx.is
npm warn deprecated @esbuild-kit/core-utils@3.3.2: Merged into tsx: https://tsx.is

No CVE — informational only — but both packages are unmaintained (superseded by tsx) and worth tracing out.

Task

• npm ls @esbuild-kit/esm-loader @esbuild-kit/core-utils to find which direct dependency still pins the
  old split packages instead of tsx.
• Bump (or override) that dependency to a version that depends on tsx directly.
• Confirm the deprecation warnings are gone from a clean npm install.
• npm run test:ci green (this touches dependency resolution broadly, not just one package).

Not urgent/blocking — informational deprecation warning, no security fix pending.

[linear-code]

JSO-5967