refactor: (re)moved some leftovers out of #588 (#599)

Author: mfranzke

source/_patterns/00-base/icons/_icons.helpers.scss

@@ -31,6 +31,10 @@
 		}
 
 		content: var(--icon-glyph-#{$position});
+		// Hiding icon from screenreaders
+		@supports (content: ""/"") {
+			content: var(--icon-glyph-#{$position}) / ""; // https://www.w3.org/TR/css-content-3/#alt
+		}
 
 		@if $partial {
 			display: inline-block;
@@ -53,9 +57,6 @@
 			/* stylelint-enable */
 
 			// Hiding icon from screenreaders
-			@supports (content: ""/"") {
-				content: var(--icon-glyph) / ""; // https://www.w3.org/TR/css-content-3/#alt
-			}
 			/* stylelint-disable */
 			-webkit-alt: "";
 			/* stylelint-enable */

source/_patterns/00-base/icons/_icons.placeholder.scss

@@ -3,8 +3,6 @@
 	-webkit-alt: "";
 	alt: "";
 
-	content: var(--icon-glyph);
-
 	display: inline-block;
 	/*** icon - placeholder ***/
 	// * use !important to prevent issues with browser extensions that change fonts
@@ -26,9 +24,6 @@
 	vertical-align: middle;
 
 	// Hiding icon from screenreaders
-	@supports (content: ""/"") {
-		content: var(--icon-glyph) / ""; // https://www.w3.org/TR/css-content-3/#alt
-	}
 	@media aural {
 		content: none;
 	}