Add Khmer translation

[FlutterRonin]

Describe the Bug

This is translation of Khmer language - Cmabodia.

Link to the code that reproduces this issue

https://github.com/FlutterRonin/payload

Reproduction Steps

This issue will work in translation in Khmer.

Which area(s) are affected?

plugin: other

Environment Info

Binaries:
  Node: 20.20.0
  npm: 10.8.2
  Yarn: N/A
  pnpm: 10.6.2
Relevant Packages:
  payload: 3.77.0
  next: 15.4.11
  @payloadcms/db-mongodb: 3.77.0
  @payloadcms/graphql: 3.77.0
  @payloadcms/next/utilities: 3.77.0
  @payloadcms/plugin-import-export: 3.77.0
  @payloadcms/richtext-lexical: 3.77.0
  @payloadcms/translations: 3.77.0
  @payloadcms/ui/shared: 3.77.0
  react: 19.2.1
  react-dom: 19.2.1
Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.6.0: Mon Jan 19 21:56:28 PST 2026; root:xnu-11417.140.69.708.3~1/RELEASE_ARM64_T6020
  Available memory (MB): 16384
  Available CPU cores: 12