[BUG]: scattergl hover freezes with more than 100.000 points all with different x but same y

[martinaquarantelli]

Description

In scattergl, when you have more than 100.000 points the scattergl freezes when trying to hover, more informations in the steps to reproduce.

Steps to reproduce

In version 4.0.0
Create a scattergl with 100.000 points with x just the index of the point and y all the same.
you can use this snipper
`const n = 100000;

Plotly.newPlot('graph', [{
type: 'scattergl',
mode: 'markers',
x0: 0,
dx: 1,
y: Array(n).fill(0)
}]);`
The default hovermode will be ok, no need to change it.
Try hovering on the point: the app freezes immediately.
Staying in the horizontal line of the points will make it look a little slow but normal, but when you exit from the line it freezes again.
Try removing one point (99.999 points): the freeze is gone.

Notes

Probably related to #6792 and #5790 but can't confirm if it's completely the same, this is more specific.
It is probably due to to the collapsation of the algorithm that comes in in a scattergl when there are TOO_MANY_POINTS (exactly 100.000).

[Lexachoc]

It seems that #7998 will solve this issue (at least for the biggest problem). The problem is that with >=100K data points, hovering will trigger a search through all points because spikedistance is set to infinity.

A workaround before the draft is merged is simply to set spikedistance: 0, although it is still a little bit laggy since all data points are in one line.