Try removing backdrop blur to see if that improves performance (#43929)

* Try removing backdrop blur to see if that improves performance

* Add transform to see that improves performance as mentioned here https://graffino.com/til/CjT2jrcLHP-how-to-fix-filter-blur-performance-issue-in-safari

* Remove blur completely again

packages/components/src/modal/style.scss

@@ -8,8 +8,7 @@
 	background-color: rgba($black, 0.35);
 	z-index: z-index(".components-modal__screen-overlay");
 	display: flex;
-	backdrop-filter: blur($grid-unit);
-
+	// backdrop-filter: blur($grid-unit);
 	// This animates the appearance of the white background.
 	@include edit-post__fade-in-animation();
 }
@@ -31,8 +30,8 @@
 		margin: auto;
 		width: auto;
 		min-width: $modal-min-width;
-		max-width: calc(100% - #{ $grid-unit-20 * 2 });
-		max-height: calc(100% - #{ $header-height * 2 });
+		max-width: calc(100% - #{$grid-unit-20 * 2});
+		max-height: calc(100% - #{$header-height * 2});
 
 		// Animate the modal frame/contents appearing on the page.
 		animation: components-modal__appear-animation 0.1s ease-out;