This commit is related to 01fa18b, which introduced an issue :
the test flow needed a mrp.bom instance, which is not a dependency of
stock_dropshipping. This commit move the test to
mrp_subcontracting_dropshipping whiwh depends of mrp.

closes odoo/odoo#75845

Signed-off-by: William Henrotin <Whenrow@users.noreply.github.com>