feat(devkit): allow requiring cts config files

[nicolas-marien]

When migrating our project to esm, we encountered an issue with the playright plugin, but more generally with the loadConfigFile from the devkit.
Our configuration is a .cts file, but it's not treated as commonjs: __dirname and __filename are not available.

Expected Behavior

.cts files are interpreted as commonJS files when in a module context.

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☁️ Nx Cloud last updated this comment at 2025-05-16 15:40:29 UTC

[jaysoo]

I think if we know that the file is specifically .cts or .mts, we can choose either require or dynamic import without having to do what load function currently does (which is try one, then try the other).

[nicolas-marien]

@jaysoo thank you for the feedback. I'll update the code accordingly.

[jaysoo]

I tested this locally. I had to make the mts use load instead of loadEsm as there might be some CJS specific contents in there like __filename. Depending on tsconfig.base.json, the modules may be transpiled as CJS anyway.

This PR now fixes the .cts issue, while maintaining same support for .ts, .mts. And for mjs, it'll go straight to loading via ESM.