Remove unused import

See gh-30886

spring-web/src/main/java/org/springframework/web/util/UriComponentsBuilder.java

@@ -31,7 +31,6 @@ import java.util.Optional;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpRequest;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;