Arrows gone from the little boxes in the table column headers

[philrz]

Repro is with Zed commit 66059b8.

Ever since Zed commit 66059b8 (associated with the changes in #3044), the little boxes in the column headers at the top of the results table have been missing, such as shown in the video below.

No-Arrows.mp4

This second video shows how those arrows looked at prior commit 18dc5e8 and earlier.

Has-Arrows.mp4

[philrz]

Verified in Zui commit b5987c1.

As shown in the attached video, the arrows in the table column headers are back.

Verify.mp4

Thanks @jameskerr!