Update dependency org.eclipse.jetty:jetty-util-ajax to v12.0.21 (#3167)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

flink-filesystems/flink-azure-fs-hadoop/pom.xml

@@ -35,7 +35,7 @@ under the License.
 	<properties>
 		<fs.azure.sdk.version>1.41.4</fs.azure.sdk.version>
 		<fs.jackson.core.version>2.9.4</fs.jackson.core.version>
-		<jetty.version>12.0.20</jetty.version>
+		<jetty.version>12.0.21</jetty.version>
 	</properties>
 
 	<dependencies>