[0.72] Bump Metro to 0.76.2, cherry pick Metro config updates

[huntie]

Summary

Cherry picks the following onto 0.72-stable:

• Bump CLI to 12.0.0-alpha.3 and Metro to 0.76.2 #36948
  • Note: Using @react-native-community/cli at 11.2.0.
• Drop internal base config merge in metro-config #36777
• Restore 'import' in default Package Exports conditions #36902
  • Versions @react-native/metro-config as 0.72.2 and updates dependency in template.

Changelog: [Internal]

Test Plan

Careful human review. Stable on main.

[github-actions]

	Warnings
⚠️	🔒 package.json - Changes were made to package.json. This will require a manual import by a Facebook employee.

Generated by 🚫 dangerJS against 41d780e

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	8,543,473	-76,818
android	hermes	armeabi-v7a	7,859,065	-73,907
android	hermes	x86	9,023,863	-82,386
android	hermes	x86_64	8,878,980	-82,090
android	jsc	arm64-v8a	9,143,879	-43,011
android	jsc	armeabi-v7a	8,335,533	-41,639
android	jsc	x86	9,199,033	-45,419
android	jsc	x86_64	9,456,890	-46,071

Base commit: 50553f4
Branch: main