Administration: Prevent horizontal scrollbar in contextual help panel.

In [62145], an ::after CSS rule was added that caused an overflow, resulting in an unintended scrollbar always appearing on Windows OS for example. This changeset removes the related CSS rule which is unnecessary to fix the initial issue.

Follow-up to [62145].

Reviewed by wildworks, SergeyBiryukov.
Merges [62187] to the 7.0 branch.

Props wildworks, SergeyBiryukov, sabernhardt, audrasjb, huzaifaalmesbah, mehrazmorshed, mukesh27.
Fixes #64744.

git-svn-id: https://develop.svn.wordpress.org/branches/7.0@62190 602fd350-edb4-49c9-b593-d223f7449a82

Author: t-hamano

src/wp-admin/css/common.css

@@ -2077,17 +2077,6 @@ p.auto-update-status {
 	box-shadow: 0 2px 0 rgba(0, 0, 0, 0.02), 0 1px 0 rgba(0, 0, 0, 0.02);
 }
 
-.contextual-help-tabs .active::after {
-	content: "";
-	position: absolute;
-	top: 0;
-	right: -1px;
-	width: 2px;
-	height: 100%;
-	background: inherit;
-	z-index: 2;
-}
-
 .contextual-help-tabs .active a {
 	border-color: #c3c4c7;
 	color: #2c3338;