_make_custom_tooltip() without tooltip text doesn't take over when mouse_filter is Pass.

[MewPurPur]

Tested versions

4.4.dev7

System information

Godot v4.4.dev7 - Pop!_OS 22.04 LTS on X11 - X11 display driver, Multi-window, 1 monitor - OpenGL 3 (Compatibility) - Mesa Intel(R) Graphics (ADL GT2) - 12th Gen Intel(R) Core(TM) i5-1235U (12 threads)

Issue description

#97961 was supposed to make it so _make_custom_tooltip() works even without custom tooltip text. But I found that this doesn't work if Mouse Filter is set to Pass. It even works with the same mouse filter when tooltip_text isn't an empty string. So the implementation of the aforementioned PR fails to work in this specific scenario.

Steps to reproduce

Implement _make_custom_tooltip() of a control, say a Button, and have it not return null. Set mouse_filter to MOUSE_FILTER_PASS. It won't work.

Minimal reproduction project (MRP)

tooltipbug.zip