Extra underscore in snapshot filename with 9.5.1 compared to 9.4.0

[ynnckcmprnl]

Context: updating Quick/Nimble/Nimble-Snapshots to the latest version coming from Quick 10.x

After adding @mainactor to our snapshot tests, all our snapshots tests were failing. When I rerecord the snapshots there's an extra underscore in the filename at the end, the actual snapshot is the same as before, the filename is not.

It seems that the name property on XCTActivity returns an extra colon which when processed causes the extra underscore. Still not quite sure why, since it's code from Apple that hasn't changed.

Behaviour with Quick 5.0.1, Nimble 10.0.0, Nimble-Snapshots 9.4.0:

Behaviour with Quick 6.1.0, Nimble 11.2.1, Nimble-Snapshots 9.5.1:

Since this hasn't been posted before, am I missing something obvious or could this be side-effect from switching to the new async approach in Quick?