Plugins: Use `include_once` for `wp-admin/includes/plugin-install.php` in `WP_Plugin_Install_List_Table::prepare_items()`.

This brings consistency with the other instances where the file is included, and allows for reusing its functions in custom code.

Props engelen, desrosj.
Fixes #38874.
Built from https://develop.svn.wordpress.org/trunk@45751


git-svn-id: http://core.svn.wordpress.org/trunk@45562 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/class-wp-plugin-install-list-table.php

@@ -85,7 +85,7 @@ class WP_Plugin_Install_List_Table extends WP_List_Table {
 	 * @global string $term
 	 */
 	public function prepare_items() {
-		include( ABSPATH . 'wp-admin/includes/plugin-install.php' );
+		include_once( ABSPATH . 'wp-admin/includes/plugin-install.php' );
 
 		global $tabs, $tab, $paged, $type, $term;
 

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-45750';
+$wp_version = '5.3-alpha-45751';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.