Revert "Make tick thicker to facilitate hovering"
Revert "Make tick thicker to facilitate hovering"

This reverts commit a90e6f1f92888e0904bd50d67993ab23ccec1a38.

uwdata/vega-lite-ui,uwdata/vega-lite-ui,vega/vega-lite-ui,vega/vega-lite-ui,vega/vega-lite-ui,uwdata/vega-lite-ui