[TASK] Remove getSubSchemaDivisorField from TcaSchema

The method is unused since #106840 and is
therefore removed.

Note: While TcaSchema is still @internal, we
kept it in v13 for b/w compatibility.

Resolves: #106859
Related: #106840
Related: #106850
Releases: main
Change-Id: If9ace34ecd94730d4e80323a388589b7a5e2093f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/89698
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oli Bartsch <bo@cedev.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Oli Bartsch <bo@cedev.de>

Author: o-ba

typo3/sysext/core/Classes/Schema/TcaSchema.php

@@ -292,14 +292,6 @@ public function getSubSchemaTypeInformation(): SchemaTypeInformation
         );
     }
 
-    public function getSubSchemaDivisorField(): ?FieldTypeInterface
-    {
-        if (isset($this->schemaConfiguration['type']) && isset($this->fields[$this->schemaConfiguration['type']])) {
-            return $this->fields[$this->schemaConfiguration['type']];
-        }
-        return null;
-    }
-
     /**
      * @return PassiveRelation[]
      */