RunConfiguration: Simplify adding of ExtraAspects

This makes the code a bit simpler, at the cost of the factories not
having access to the fully specialized RunConfiguration anymore. This
is apparently never used and the factories can still use the Id to decide
what to do if they really need to.

Change-Id: I7d94f85e984ac87e62c6d341c1038e1538aa15df
Reviewed-by: hjk <hjk@qt.io>

src/plugins/projectexplorer/target.cpp

@@ -398,7 +398,6 @@ void Target::addRunConfiguration(RunConfiguration *rc)
 {
     QTC_ASSERT(rc && !d->m_runConfigurations.contains(rc), return);
     Q_ASSERT(rc->target() == this);
-    rc->addExtraAspects();
 
     // Check that we don't have a configuration with the same displayName
     QString configurationDisplayName = rc->displayName();