fix errors in note for ExpressionBuilder::as (#6384)

* fix errors in note for ExpressionBuilder::as

The ExpressionBuilder class has neither a for nor a select method. It is the QueryBuilder instead. And the Select has no alias parameter. 

I cannot understand what is meant with the reducing of nesting by using an alias.

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* Apply suggestions from code review

Co-authored-by: Lina Wolf <48202465+linawolf@users.noreply.github.com>

* Apply suggestion from @linawolf

* Apply suggestion from @linawolf

* Apply suggestion from @linawolf

* Apply suggestion from @linawolf

---------

Co-authored-by: Lina Wolf <48202465+linawolf@users.noreply.github.com>

Author: franzholz

Documentation/ApiOverview/Database/DoctrineDbal/ExpressionBuilder/Index.rst

@@ -186,7 +186,7 @@ Creates a statement to append a field alias to a value, identifier or sub-expres
 
 ..  note::
 
-    Some :php:`ExpressionBuilder` methods (like :php:`select()` and :php:`from()`) provide an argument to directly add
+    Some :php-short:`\TYPO3\CMS\Core\Database\Query\QueryBuilder` methods (like :php:`select()` and :php:`from()`) provide an argument to directly add
     the expression alias to reduce nesting. This new method can be used for
     custom expressions and avoids recurring conditional quoting and alias appending.