data-tests can't handle "?"

[plehegar]

Description of problem

URL to affected spec or repo:

https://w3c.github.io/pointerevents/

What happened (e.g., it crashed)?:

When one uses
data-tests="pointerevent_pointermove_isprimary_same_as_pointerdown.html?mouse"

Respec generates an invalid warning :

The following test could not be found in Web Platform Tests: pointerevent_pointermove_isprimary_same_as_pointerdown.html?mouse.

Expected behavior (e.g., it shouldn't crash):

No warning.

The file exists:
https://github.com/web-platform-tests/wpt/blob/master/pointerevents/pointerevent_pointermove_isprimary_same_as_pointerdown.html

but uses a parameter to run properly.

wpt.fyi does report results:

https://wpt.fyi/results/pointerevents/pointerevent_pointermove_isprimary_same_as_pointerdown.html%3Fmouse?label=experimental&label=master&aligned

Optional, steps to reproduce:

1. Add the data-tests attribute
2. reload the document and see the warning

https://github.com/speced/respec/blob/main/src/core/linter-rules/wpt-tests-exist.js#L36 should probably add

.map(test => test.trim().split("?")[0])

I'll make a PR unless someone believes differently.

[TimvdLippe]

Seems like a legitimate fix to me (external contributor, not a maintainer)