Fix -Wtemplate-id-cdtor compiler warning

Fixes:
```
objectmodelbase.h:47:36: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
   47 |     explicit ObjectModelBase<Base>(QObject *parent)
      |                                    ^~~~~~~
```

core/objectmodelbase.h

@@ -44,7 +44,7 @@ class ObjectModelBase : public Base
      * Constructor.
      * @param parent is the parent object for this instance.
      */
-    explicit ObjectModelBase<Base>(QObject *parent)
+    explicit ObjectModelBase(QObject *parent)
         : Base(parent)
     {
     }