Delete editor-styles (#21383)

These were used to prevent wp-admin styles from leaking to the editor. Now that the paragraph & heading blocks add their own variables for these properties, we can remove these styles.

packages/editor/src/editor-styles.scss

@@ -42,17 +42,6 @@ h6 {
 	font-size: 0.8em;
 }
 
-// Adjust line spacing for larger headings.
-h1,
-h2,
-h3 {
-	line-height: 1.4;
-}
-
-h4 {
-	line-height: 1.5;
-}
-
 // Default margins.
 h1 {
 	margin-top: 0.67em;
@@ -84,15 +73,6 @@ h6 {
 	margin-bottom: 2.33em;
 }
 
-h1,
-h2,
-h3,
-h4,
-h5,
-h6 {
-	color: inherit;
-}
-
 p {
 	font-size: inherit;
 	margin-top: $default-block-margin;