Fix icon rebase regression.

packages/components/src/button/style.scss

@@ -12,11 +12,17 @@
 	height: $icon-button-size;
 	align-items: center;
 	box-sizing: border-box;
-	padding: 8px;
+	padding: 6px; // Centers 24px icons.
 	overflow: hidden;
 	border-radius: 2px;
 	color: $black;
 
+	// Legacy 20px icons get 2px margin to have a 24px dimensions, making them centered.
+	> .dashicon,
+	> svg[width="20"] {
+		margin: 0 2px;
+	}
+
 	&:not(:disabled):not([aria-disabled="true"]):not(.is-secondary):not(.is-primary):not(.is-tertiary):not(.is-link):hover {
 		color: $theme-color;
 	}
@@ -220,12 +226,6 @@
 		&.has-text svg {
 			margin-right: 8px;
 		}
-
-		// Icon buttons without text should be squared.
-		&:not(.has-text) {
-			width: 36px;
-			justify-content: center;
-		}
 	}
 
 	svg {