fix(macos): import <RCTUIKit/RCTUIKit.h> in RCTSwiftUIWrapper for static builds

`RCTSwiftUIContainerViewWrapper.h` imported `<React/RCTUIKit.h>`, which
resolved directly when React-RCTUIKit used `header_dir "React"` before the
0.83 merge. After merging main's RCTUIKit relocation (#2943), React-RCTUIKit
uses `header_dir "RCTUIKit"` and `<React/RCTUIKit.h>` is only a React-Core
forwarding header. RCTSwiftUIWrapper depends on React-RCTUIKit (not
React-Core), so the forwarding header is out of scope and static-library
builds failed:

    RCTSwiftUIContainerViewWrapper.h:9:9: 'React/RCTUIKit.h' file not found
      (in target 'RCTSwiftUIWrapper-macOS')

Import the header directly from the React-RCTUIKit dependency
(`<RCTUIKit/RCTUIKit.h>`). Verified locally: `RCTSwiftUIWrapper-macOS`
builds (BUILD SUCCEEDED) against the static-library Pods project.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>