fix(product): Correctly fetch category descendants by handle (#13579)

This PR fixes the issue #13518  where product category descendants were not retrieved when
filtering by handle with the include_descendants_tree flag. The handle filter was not
being correctly removed before the descendant tree query was executed.

.changeset/cuddly-kiwis-roll.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/product": patch
+---
+
+fix(product): Correctly fetch category descendants by handle