Fix grammatical errors in Javadoc

Closes gh-27298

spring-webmvc/src/main/java/org/springframework/web/servlet/function/RequestPredicate.java

@@ -71,7 +71,7 @@ public interface RequestPredicate {
 
 	/**
 	 * Transform the given request into a request used for a nested route. For instance,
-	 * a path-based predicate can return a {@code ServerRequest} with a the path remaining
+	 * a path-based predicate can return a {@code ServerRequest} with a path remaining
 	 * after a match.
 	 * <p>The default implementation returns an {@code Optional} wrapping the given request if
 	 * {@link #test(ServerRequest)} evaluates to {@code true}; or {@link Optional#empty()}