chore: Upgrade JS tooling stack to latest

[mrousavy]

Summary

Consolidates the remaining JS tooling package upgrade PRs into one branch:

• Babel tooling: @babel/core, @babel/preset-env, @babel/runtime, and babel-plugin-module-resolver
• react-native-builder-bob 0.41
• TypeScript 6.0.3, typescript-eslint 8.60.0, and @tsconfig/react-native 3.0.9
• ESLint 9.39.4 flat-config migration via eslint.config.mjs

ESLint 10.x is available on npm, but @react-native/eslint-config@0.85.3 only peers ^8 || ^9, so this keeps ESLint on the latest compatible 9.x maintenance release instead of forcing an unsupported major.

Prior PR inspection

• chore: Upgrade Babel tooling to 7.29.7 #1355 Babel: source branch retained the intended package updates; the PR itself was already closed/no-checks after its branch briefly matched main.
• chore: Upgrade react-native-builder-bob to 0.41.0 #1358 builder-bob: typecheck, lint, Android build, Vercel, and Nitrogen checks were green on the rebased branch; harness jobs were still pending when consolidated.
• chore: Upgrade TypeScript toolchain to 6.0.3 #1359 TypeScript: typecheck, lint, Android build, Vercel, and Nitrogen checks were green on the rebased branch; harness jobs were still pending when consolidated.
• chore: Upgrade ESLint tooling to 9.39.4 #1360 ESLint: full CI was green, including build, lint, Vercel, Nitrogen, and harness.

Validation

• bun install (including postinstall build)
• bun run build
• bun typecheck
• package bun lint-ci for example, nitrogen, nitro-test-external, nitro-test, and nitro-modules
• package bun lint auto-fix pass for the same workspaces
• bun --cwd docs build

Follow-up

• Opened upstream Bob PR to resolve hoisted TypeScript binaries: fix: resolve hoisted tsc binaries callstack/react-native-builder-bob#944
• Once Bob releases that fix, remove the temporary explicit tsc path from packages/react-native-nitro-modules/package.json.

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Project	Deployment	Actions	Updated (UTC)
nitro-docs	Ready	Preview, Comment	May 28, 2026 1:59pm