Revert "Use Codex styles for buttons in language overlay"

This reverts commit d29050d080.

Reason for revert: I had mistakenly assumed the @wikimedia/codex
module was loaded on clicking the language button. It appears to
be added on page load.

Given T248718 it's still unclear what our policy on loading
@wikimedia/codex on page load is and given several people are out
I think it would be better to attempt this again next week, possibly
delaying further if needed.

Bug: T353071
Bug: T248718
Change-Id: I09334a1faec06a7400e61013ddda374156bf5d72

resources/css/ext.uls.displaysettings.less

@@ -9,8 +9,7 @@
 .uls-button-group {
 	display: inline-block;
 	position: relative;
-	// The 1px are needed to handle overflow in .cdx-button-group in 1.39
-	padding: 1px 0 0 1px;
+	padding: 0;
 	left: -20px;
 	z-index: 1;
 }

resources/css/ext.uls.inputsettings.less

@@ -96,8 +96,8 @@
 	}
 }
 
-.uls-input-settings .cdx-radio {
-	position: relative;
+.uls-input-settings-inputmethods-list .mw-ui-radio {
+	display: block;
 }
 
 .uls-ime-notification-bubble .link {

resources/css/ext.uls.languagesettings.less

@@ -130,20 +130,14 @@
 	margin-left: 15px;
 }
 
-// This can be removed when 1.39 support is dropped.
-.uls-input-settings-inputmethods-list .cdx-radio__label,
-.checkbox.cdx-checkbox__label {
-	padding-left: ~'calc(1.25em + 8px)';
-}
-
 .uls-ui-languages p,
 .checkbox {
 	color: @color-subtle;
 	font-size: 10pt;
 }
 
-/* @todo: Amend to use Codex when 1.39 support is no longer needed. */
-#languagesettings-panels .uls-cdx-button-pressed {
+/* mediawiki.ui does not have a pressed state style. */
+#languagesettings-panels .mw-ui-pressed {
 	background-color: @background-color-progressive--active;
 	color: @color-inverted;
 	border-color: @border-color-progressive--active;