fix(compiler): conditionally restore prop: branch in OneOf helper

[rajat12826]

Description

This PR fixes an issue where objects could no longer be passed to required aria-* props via JSX (prop:aria={...}) since 4.44.0.

Because Stencil's HTMLAttributes includes a template literal index signature for aria${string}, passing an object shape to a required aria prop fails standard property assignment. The prop:aria prefix historically bypassed this, but #6804 removed the prop: branch from the generated OneOf helper entirely to prevent TS2590 ("union type too complex") on components with 8+ required props.

The Fix:
This PR re-introduces the 3-way exclusive branch version of OneOf (which supports the prop: option) conditionally, only for components with 5 or fewer required props (MAX_ONE_OF_REQUIRED_PROPS_WITH_PROP = 5).

This cleanly balances both needs:

1. Standard UI components (≤5 required props) regain the ability to use prop: overrides for complex types that overlap with standard HTML attributes.
2. Components with many required props (6 to 8) continue to use the 2-way exclusive branch, ensuring they do not trigger the TS union size limits that bug: Required @Prop() declarations generate excessively complex JSX types in components.d.ts #6799/fix(compiler): too many required props / "union type too complex" #6804 originally resolved.

Related Issue(s)

Fixes #6854

Testing

• Verified prop:aria={{ 'aria-label': 'Close' }} compiles correctly for components below the 5-prop threshold.
• Verified TypeScript union constraints remain within limits for components with up to 8 required properties.