Timeline does not zoom when ctrl+scroll wheel are used when Rerun does not have focus

[andybarry]

Describe the bug
When the cursor is over the timeline, Ctrl is pressed, and scroll wheel is used Rerun zooms the timeline.

When Rerun does not have focus, however, Ctrl is ignored and the scroll wheel will scroll down regardless.

To Reproduce
Steps to reproduce the behavior:

1. Open Rerun and put something on the timeline
2. Use Ctrl+scroll wheel on the timeline to observe zoom
3. Click into another app so that Rerun does not have focus
4. Without clicking back into Rerun, observe that the timeline will scroll when the user hovers over it and scrolls.
5. Without clicking back into Rerun, not that Ctrl is ignored when using scroll wheel

Expected behavior
Rerun respects Ctrl when zooming on the timeline, even without focus. Note that other applications, like Firefox do respect Ctrl in this case.

Desktop (please complete the following information):
Operating System: Ubuntu 22.04
KDE Plasma Version: 5.24.7
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.3
Kernel Version: 6.8.0-40-generic (64-bit)
Graphics Platform: X11
Processors: 32 × Intel® Core™ i9-14900KF
Memory: 62.6 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 4090/PCIe/SSE2

Rerun version

rerun-cli 0.18.2 [rustc 1.76.0 (07dca489a 2024-02-04), LLVM 17.0.6] x86_64-unknown-linux-gnu 7312/merge 59ff15b, built 2024-08-29T13:49:48Z

cc @nikolausWest, @gavrelina

[abey79]

I cannot reproduce on macOS. Ctrl-scroll wheel works regardless of whether the rerun window is focused or not.

I suspect that this might be a platform-specific limitation (or bug) in winit. This comment seems vaguely related, though I'm not able to dive into the details or test on linux right now.

In any case, I'm afraid we won't be able to fix this by 0.21, so I'm removing it from the milestone.