Regression in [0] which would re-highlight gizmos when they had been
tagged for highlighting.
This caused highlighting to be recalculated unexpectedly while
blocking modal operators run that used a timer.
The timer events would be passed though to the gizmo handler which
then re-evaluated the highlighted gizmo based on the cursor position.
Resolve by skipping pass-through for gizmos.
[0]: f839847d3b4849425c3b06a52aae4361d384fea4
534044ccef