Fix typo in Javadoc in HeaderAssertions

Closes gh-27589

Author: Xxpain

spring-test/src/main/java/org/springframework/test/web/reactive/server/HeaderAssertions.java

@@ -115,7 +115,7 @@ public WebTestClient.ResponseSpec valueMatches(String name, String pattern) {
 	/**
 	 * Match all values of the response header with the given regex
 	 * patterns which are applied to the values of the header in the
-	 * same order. Note that the number of pattenrs must match the
+	 * same order. Note that the number of patterns must match the
 	 * number of actual values.
 	 * @param name the header name
 	 * @param patterns one or more regex patterns, one per expected value