Upgrade parent pom to 0.26.0 and switching to Java 17 for compilation.

Author: janvanmansum

pom.xml

@@ -22,7 +22,7 @@
     <parent>
         <groupId>nl.knaw.dans</groupId>
         <artifactId>dd-parent</artifactId>
-        <version>0.25.0</version>
+        <version>0.26.0</version>
     </parent>
 
     <artifactId>dd-dataverse-authenticator</artifactId>