fix: Make SPACspNonceFilter non final to avoid CGLIB subclass generation error

Author: jornfranke

backend/src/main/java/eu/zuinnote/example/springwebdemo/configuration/SPACspNonceFilter.java

@@ -26,7 +26,7 @@
 import org.springframework.web.util.ContentCachingResponseWrapper;
 
 @Component
-public final class SPACspNonceFilter implements Filter {
+public class SPACspNonceFilter implements Filter {
 
     private static final String NONCE_PREFIX = "nonce-";
     private static final int NONCE_SIZE = 64;