feat: support tsx for TypeScript config loading

[chiddekel]

Summary

• Add tsx/cjs as an automatic interpret/rechoir fallback loader for TypeScript webpack config files.
• Preserve the existing loader order by appending tsx/cjs after the loaders already provided by interpret.
• Add a focused TypeScript config fixture that proves webpack --mode=production works when only tsx is available for TypeScript config loading.

Test plan

• git diff --check origin/main...HEAD
• /home/developer/.cache/ms-playwright-go/1.57.0/node --check test/build/config-format/typescript-tsx/typescript.test.mjs
• find test/build/config-format/typescript-tsx/node_modules -type f -name '*.js' -print -exec /home/developer/.cache/ms-playwright-go/1.57.0/node --check {} \;
• /home/developer/.cache/ms-playwright-go/1.57.0/node -e "require('./node_modules/tsx/cjs'); const config = require('./webpack.config.ts'); console.log(config.entry, config.output.filename);"

Full Jest/build verification was not run in this environment because node/npm are not on PATH and project dependencies are not installed.

[changeset-bot]

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Latest commit: 516ea6e

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[linux-foundation-easycla]

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