fix(macos): align TouchableBounce & AccessibilityInfo with upstream (#3009)

## Summary

Supersedes #2964. Two small JS fixes from the 0.83 merge audit.

**`TouchableBounce.js`** — add the `onPress !== undefined` guard to the
macOS `focusable` check (matches upstream 0.83). A `TouchableBounce`
with no `onPress` is no longer Tab/VoiceOver focusable.

**`AccessibilityInfo.js`** — drop the macOS carve-outs in
`isBoldTextEnabled` and `isReduceTransparencyEnabled` so both use
upstream's android-first guard and fall through to native on macOS, like
their siblings (`isReduceMotionEnabled`, `isInvertColorsEnabled`):
- `isReduceTransparencyEnabled` now returns the real macOS "Reduce
Transparency" setting instead of a hardcoded `false` — the native side
already tracks and live-updates it.
- `isBoldTextEnabled` still returns `false` on macOS (no native value),
now with zero fork divergence.

Both methods now match upstream exactly, aside from the fork-wide
`NativeAccessibilityManagerApple` rename.

## Test plan

- macOS: `isReduceTransparencyEnabled` reflects the System Settings
toggle; `isBoldTextEnabled` stays `false`.
- `TouchableBounce` without `onPress` is not focusable.
- iOS / Android unchanged; no type changes.

Related: #2901.

Co-authored-by: Thiago Vinhas <thiago@vinhas.net>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>