Move dependency mapping to TestCase

The `TestCaseFactory::getClassName` was removed since it can have
unexpected results when called too early, as it builds up the test class
prematurely. It is not currently used anywhere else.

src/Factories/TestCaseFactory.php

@@ -156,14 +156,6 @@ final class TestCaseFactory
         return array_map($createTest, array_keys($datasets), $datasets);
     }
 
-    /**
-     * Makes a fully qualified class name from the current filename.
-     */
-    public function getClassName(): string
-    {
-        return $this->makeClassFromFilename($this->filename);
-    }
-
     /**
      * Makes a fully qualified class name from the given filename.
      */