fix: Light mode colors in the make mutable example in docs

[MatiPl01]

Summary

I used useColorScheme hook from react-native instead of the one from the @mui/material library, which returned 'dark' color scheme name irrespective of the actual selected theme.

This PR changes the hook to the correct one which fixes the text color in the light mode.

Example screenshots

Light theme

Before	After

Dark theme

Works fine, as before.

Before	After

Test plan

• cd packages/reanimated-docs,
• yarn start,
• navigate to the makeMutable page in docs and see the example

[bartlomiejbloniarz]

🚀