Docs: Remove @static notations from method DocBlocks in wp-includes/* classes.

This tag has been used in the past, but should no longer be used. Just using the `static` keyword in code is enough for PhpDocumentor on PHP5+ to recognize static variables and methods, and PhpDocumentor will mark them as static.

Props birgire.
See #42803.

git-svn-id: https://develop.svn.wordpress.org/trunk@42746 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/rest-api/class-wp-rest-request.php

@@ -174,7 +174,6 @@ class WP_REST_Request implements ArrayAccess {
 	 * @link https://nginx.org/en/docs/http/ngx_http_core_module.html#underscores_in_headers
 	 *
 	 * @since 4.4.0
-	 * @static
 	 *
 	 * @param string $key Header name.
 	 * @return string Canonicalized name.
@@ -953,7 +952,6 @@ class WP_REST_Request implements ArrayAccess {
 	/**
 	 * Retrieves a WP_REST_Request object from a full URL.
 	 *
-	 * @static
 	 * @since 4.5.0
 	 *
 	 * @param string $url URL with protocol, domain, path and query args.