Fix Mac Unit Tests in AR

[EnterTheArcane]

What does this PR do?

Fixes the Mac-Test job on current GitHub-hosted macOS runners and enables it for normal AR runs, not just manual workflow dispatches.

The first blocker was the macOS Qt package linking QtDBus, even though O3DE doesn't use it. This updates Qt to 6.10.2-rev7, built without D-Bus by o3de/3p-package-source#399.

The remaining changes address failures exposed once the tests could launch, including FileWatcher shutdown behavior, named-pipe file-length queries, task tests under limited worker counts, and a SIMD mask implementation that passed on ARM but crashed Windows tests.

A few test changes are worth calling out:

• The manipulator test now uses a pick bound large enough to cover an actual pixel at its configured depth. It still validates both the resulting screen position and world-space translation.
• Screen/world round trips allow up to two pixels of rounding error. Integer screen coordinates produced an observed two-pixel difference at a viewport corner.
• Signed BC4/BC5 formats are removed from a generic color-compression loop and covered by dedicated production-compressor tests instead.
• The PhysX vertex comparison now matches the unordered vertex sets within the existing tolerance rather than relying on unstable lexicographic sorting.
• A few focus-transition tests still use the deprecated QApplication::setActiveWindow. The warning suppression is scoped to those calls. I left a note to refactor the tests so we can remove it later.

How was this PR tested?

• Built the affected Profile targets with unity disabled and three parallel build workers.
• Passed the complete AzCore, AzToolsFramework, EditorLib, ImageProcessingAtom.Editor, and AtomToolsFramework test suites.
• Verified the updated Qt package has no QtDBus linkage and has valid signatures.

AR will cover Windows and Linux. The previous Windows failure was traced to the SIMD mask aliasing and was replaced with the platform SIMD integer-load and bit-cast APIs.