fix: revert additional two-way-binding checks

[dummdidumm]

This reverts #2477. Sadly, the idea didn't work out, as shown by two opened bug reports:

• Component Prop TypeScript Regression #2506: A type union can be narrowed on the input, but not on the way back out
• Svelte 5: Binding on Generic Props shows error #2494: A generic nested within a bound value is not properly resolved and not falling back to any (in feat: better type checking for bindings in Svelte 5 #2477 we thought of the generic case, but only for when the generic is the whole value type, not when it's nested)

For these reasons I don't see a way to properly implement #1392 at the moment.