[charts][code-infra] Remove webkit test differences

[JCQuintas]

Remove isWebkit checks across gesture tests. Seems it was fixed somewhere along the line in the upstream deps

[mui-bot]

Deploy preview: https://deploy-preview-20707--material-ui-x.netlify.app/

Bundle size report

Bundle	Parsed size	Gzip size
@mui/x-data-grid	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-pro	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-premium	0B(0.00%)	0B(0.00%)
@mui/x-charts	0B(0.00%)	0B(0.00%)
@mui/x-charts-pro	0B(0.00%)	0B(0.00%)
@mui/x-charts-premium	0B(0.00%)	0B(0.00%)
@mui/x-date-pickers	0B(0.00%)	0B(0.00%)
@mui/x-date-pickers-pro	0B(0.00%)	0B(0.00%)
@mui/x-tree-view	0B(0.00%)	0B(0.00%)
@mui/x-tree-view-pro	0B(0.00%)	0B(0.00%)

Details of bundle changes

Generated by 🚫 dangerJS against bad2f91

[codspeed-hq]

CodSpeed Performance Report

Merging #20707 will not alter performance

_{Comparing JCQuintas:remove-webkit-fixes (bad2f91) with master (bbb4743)¹}

Summary

✅ 14 untouched

Footnotes

1. No successful run was found on master (a1ec342) during the generation of this report, so bbb4743 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩