Twenty Twenty-One: Remove spacer block styles.

The theme includes styles for the spacer block for the front which appears to be unnecessary:
* It adds `display: block` even though that is the default.
* It removes top and bottom margin, even though this is not needed in the post content because of collapsing margins between blocks.
* It uses a custom CSS property to force a specific height on mobile. This affects the patterns in the theme negatively.

It also causes styling problems:
* When the spacer block has a height set to `0` in the navigation block, as the theme forces this to be larger on smaller screens.
* When the block is horizontal. Horizontal was not an option when this style was added.

Consequences of removal:
* Removing the use of the custom CSS property will cause a style change for websites that have adjusted the spacing property.

Follow-up to [49216], [49574].

Props poena, mukesh27.
Fixes #56222.
Built from https://develop.svn.wordpress.org/trunk@54103

wp-content/themes/twentytwentyone/assets/css/ie.css

@@ -66,7 +66,6 @@ Twenty Twenty-One is distributed under the terms of the GNU GPL.
  * Quote................Specific styles for the quote block.
  * Search...............Specific styles for the search block.
  * Separator............Specific styles for the separator block.
- * Spacer...............Specific styles for the spacer block.
  * Table................Specific styles for the table block.
  * Verse................Specific styles for the verse block.
  * Video................Specific styles for the video block.
@@ -4371,18 +4370,6 @@ hr.wp-block-separator.is-style-dots:before {
 	background: none;
 }
 
-.wp-block-spacer {
-	display: block;
-	margin-bottom: 0 !important;
-	margin-top: 0 !important;
-}
-@media only screen and (max-width: 481px) {
-
-	.wp-block-spacer[style] {
-		height: 20px !important;
-	}
-}
-
 table,
 .wp-block-table {
 	width: 100%;

wp-content/themes/twentytwentyone/assets/sass/05-blocks/blocks.scss

@@ -29,7 +29,6 @@
 @import "search/style";
 @import "separator/style";
 @import "social-icons/style";
-@import "spacer/style";
 @import "table/style";
 @import "tag-clould/style";
 @import "verse/style";

wp-content/themes/twentytwentyone/assets/sass/style.scss

@@ -47,7 +47,6 @@
  * Quote................Specific styles for the quote block.
  * Search...............Specific styles for the search block.
  * Separator............Specific styles for the separator block.
- * Spacer...............Specific styles for the spacer block.
  * Table................Specific styles for the table block.
  * Verse................Specific styles for the verse block.
  * Video................Specific styles for the video block.

wp-content/themes/twentytwentyone/style-rtl.css

@@ -66,7 +66,6 @@ Twenty Twenty-One is distributed under the terms of the GNU GPL.
  * Quote................Specific styles for the quote block.
  * Search...............Specific styles for the search block.
  * Separator............Specific styles for the separator block.
- * Spacer...............Specific styles for the spacer block.
  * Table................Specific styles for the table block.
  * Verse................Specific styles for the verse block.
  * Video................Specific styles for the video block.
@@ -3375,18 +3374,6 @@ hr.wp-block-separator.is-style-dots:before {
 	background: none;
 }
 
-.wp-block-spacer {
-	display: block;
-	margin-bottom: 0 !important;
-	margin-top: 0 !important;
-}
-@media only screen and (max-width: 481px) {
-
-	.wp-block-spacer[style] {
-		height: var(--global--spacing-unit) !important;
-	}
-}
-
 table,
 .wp-block-table {
 	width: 100%;

wp-content/themes/twentytwentyone/style.css

@@ -66,7 +66,6 @@ Twenty Twenty-One is distributed under the terms of the GNU GPL.
  * Quote................Specific styles for the quote block.
  * Search...............Specific styles for the search block.
  * Separator............Specific styles for the separator block.
- * Spacer...............Specific styles for the spacer block.
  * Table................Specific styles for the table block.
  * Verse................Specific styles for the verse block.
  * Video................Specific styles for the video block.
@@ -3385,18 +3384,6 @@ hr.wp-block-separator.is-style-dots:before {
 	background: none;
 }
 
-.wp-block-spacer {
-	display: block;
-	margin-bottom: 0 !important;
-	margin-top: 0 !important;
-}
-@media only screen and (max-width: 481px) {
-
-	.wp-block-spacer[style] {
-		height: var(--global--spacing-unit) !important;
-	}
-}
-
 table,
 .wp-block-table {
 	width: 100%;

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-alpha-54102';
+$wp_version = '6.1-alpha-54103';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.