Bump jjwt.version from 0.12.6 to 0.13.0 (#425)

Author: Copilot

xapi-model/src/main/java/dev/learning/xapi/model/Statement.java

@@ -131,7 +131,7 @@ public Statement signAndBuild(PrivateKey privateKey) {
                     .length(token.length())
                     .contentType("application/octet-stream"));
 
-      } catch (final UnknownClassException e) {
+      } catch (final UnknownClassException | ExceptionInInitializerError e) {
         throw new IllegalStateException(
             """