Coding Standards: Remove stale WPCS inline comments in Twenty Nineteen

The `// WPCS: XSS OK.` comments use a legacy annotation format no longer
recognized by PHPCS.

This format was introduced in WPCS 0.4.0, deprecated in WPCS 2.0.0 (see
WordPress/WordPress-Coding-Standards 1580), and support was fully removed
in WPCS 3.0.0 (see WordPress/WordPress-Coding-Standards 1908) in favor of
the PHPCS native `phpcs:ignore` annotations.

Additionally, the `WordPress.Security.EscapeOutput` sniff these comments
reference is part of the `WordPress-Extra` standard, not the
`WordPress-Core` standard used in this repository.

Author: rodrigoprimo

src/wp-content/themes/twentynineteen/inc/template-tags.php

@@ -92,7 +92,7 @@ function twentynineteen_entry_footer() {
 					/* translators: Hidden accessibility text. */
 					__( 'Posted in', 'twentynineteen' ),
 					$categories_list
-				); // WPCS: XSS OK.
+				);
 			}
 
 			$tags_list = get_the_tag_list( '', wp_get_list_item_separator() );
@@ -104,7 +104,7 @@ function twentynineteen_entry_footer() {
 					/* translators: Hidden accessibility text. */
 					__( 'Tags:', 'twentynineteen' ),
 					$tags_list
-				); // WPCS: XSS OK.
+				);
 			}
 		}