Upgrade to nullability plugin 0.0.11

Closes gh-1770

Author: snicoll

gradle/plugins/gradle.properties

@@ -2,4 +2,4 @@ assertJVersion=3.25.3
 gradleVersionsPluginVersion=0.53.0
 javaFormatVersion=0.0.47
 junitVersion=6.0.1
-nullabilityPluginVersion=0.0.10
+nullabilityPluginVersion=0.0.11

spring-ws-core/src/main/java/org/springframework/ws/server/endpoint/support/PayloadRootUtils.java

@@ -36,7 +36,6 @@
 import org.xml.sax.InputSource;
 import org.xml.sax.XMLReader;
 
-import org.springframework.lang.Contract;
 import org.springframework.xml.namespace.QNameUtils;
 import org.springframework.xml.transform.TransformerHelper;
 import org.springframework.xml.transform.TraxUtils;
@@ -59,7 +58,6 @@ private PayloadRootUtils() {
 	 * not a {@code DOMSource}
 	 * @return the root element, or {@code null} if {@code source} is {@code null}
 	 */
-	@Contract("!null, _ -> !null")
 	public static @Nullable QName getPayloadRootQName(@Nullable Source source, TransformerFactory transformerFactory)
 			throws TransformerException {
 		return getPayloadRootQName(source, new TransformerHelper(transformerFactory));