Remove the method that is already backported to core

src/wp-includes/class-wp-theme-json.php

@@ -759,21 +759,6 @@ public function get_template_parts() {
 		return $template_parts;
 	}
 
-	/**
-	 * Returns the current theme's wanted patterns(slugs) to be registered from
-	 * Pattern Directory.
-	 *
-	 * @since 6.0.0
-	 *
-	 * @return array Array of patterns if configured, else empty array.
-	 */
-	public function get_patterns() {
-		if ( isset( $this->theme_json['patterns'] ) && is_array( $this->theme_json['patterns'] ) ) {
-			return $this->theme_json['patterns'];
-		}
-		return array();
-	}
-
 	/**
 	 * Converts each style section into a list of rulesets
 	 * containing the block styles to be appended to the stylesheet.