Fixes file drag and drop does not open the explorer pane

[jeanp413]

This PR fixes #87596

[isidorn]

I have verified this PR fixes the linked issue, thus adding approved.
However I do not fully understand how this fixes it, it would be great if you could clarify a bit @jeanp413

Did we loose this css rule with our refactorings maybe? @sbatten
Also adding @sbatten as reviewer
fyi @sandy081

[jeanp413]

@isidorn sure.
The issue was caused by the addition of the activity bar indicator because its over the label and badge preventing them from firing the dragover event.
Adding pointer-events: none to the activity bar indicator makes it ignore pointer events and allows the elements underneath become the target of pointer events.

[isidorn]

Makes perfect sense. Due to that merging this in
fyi @misolori since you added the activity bar indicator.