[fix] Fix SysONContentAdapter

#2174 updated the condition
of the addAdapter method.
This fix applies the same condition to the removeAdapter, to be
consistent and avoid leaks.

Signed-off-by: Axel RICHARD <axel.richard@obeo.fr>

Author: AxelRICHARD

backend/services/syson-services/src/main/java/org/eclipse/syson/util/SysONEContentAdapter.java

@@ -58,7 +58,7 @@ protected void addAdapter(Notifier notifier) {
 
     @Override
     protected void removeAdapter(Notifier notifier) {
-        if (notifier instanceof Element element && (!(notifier instanceof Membership) || notifier instanceof FeatureValue)) {
+        if (notifier instanceof Element element && (!(notifier instanceof Membership) || this.shouldCacheMembership(notifier))) {
             EClass eClass = element.eClass();
             List<EObject> value;
             if (this.cache.containsKey(eClass)) {