chore: Add separate tsconfig for metro-config

[tjzel]

Summary

Including both src and metro-config in tsconfig.json of Reanimated package sometimes falsely suggests TypeScript that there should be lib/module/src and lib/module/metro-config directories.

Test plan

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[MatiPl01]

I wouldn't say that it suggests that there should be a separate directory in the built library as the react-native-builder-bob field in the package.json specifies which directories should be included in the build process.

To me, adding metro-config directory to the include array in the tsconfig just says that the same typescript configuration should be used for this directory as for the src.

It makes no difference to me which approach we decide to use, so if you prefer this implementation, let's merge this PR.