General: Removing static from wp_get_wp_version().

Removes the static storing the version number in `wp_get_wp_version()` to ensure the version number is reported correctly after a WordPress upgrade is completed.

Reverts [58827].

Props costdev, SergeyBiryukov, Cybr.
See #61782.


git-svn-id: https://develop.svn.wordpress.org/trunk@58848 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/functions.php

@@ -8819,11 +8819,7 @@ function clean_dirsize_cache( $path ) {
  * @return string The current WordPress version.
  */
 function wp_get_wp_version() {
-	static $wp_version;
-
-	if ( ! isset( $wp_version ) ) {
-		require ABSPATH . WPINC . '/version.php';
-	}
+	require ABSPATH . WPINC . '/version.php';
 
 	return $wp_version;
 }