Bump target JDK to 21

Change-Id: Ibbe0d6450c9d54018d8b883332d7e351f286e603
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 49504ef..172986e 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="17" project-jdk-type="JavaSDK" />
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" project-jdk-name="17" project-jdk-type="JavaSDK" />
 </project>
\ No newline at end of file