Remove SuperAccess::getType()

This had a bad effect on our call resolution, so I'm reverting it for
now. We may want to diverge from the language specification here.

ql/src/codeql_ql/ast/Ast.qll

@@ -1661,8 +1661,6 @@ class ThisAccess extends Identifier {
 class Super extends TSuper, Expr {
   Super() { this = TSuper(_) }
 
-  override Type getType() { result = this.getParent+().(Class).getType() }
-
   override string getAPrimaryQlClass() { result = "SuperAccess" }
 }