The dropshipping case is missing when creating an invoice from pickings

[anpartner]

https://github.com/OCA/account-invoicing/blob/23da0d6ffa74d9d5ca4fda22910e63f5beeb4b8b/stock_picking_invoicing/wizards/stock_invoice_onshipping.py#L20

`INVOICE_TYPE_MAP = {

Picking Type Code | Local Origin Usage | Local Dest Usage

("outgoing", "internal", "customer"): "out_invoice",
("incoming", "customer", "internal"): "out_refund",
("incoming", "customer", "customer"): "out_refund",
("incoming", "supplier", "internal"): "in_invoice",
("outgoing", "internal", "supplier"): "in_refund",
("outgoing", "internal", "internal"): "in_refund",
("incoming", "transit", "internal"): "in_invoice",
("outgoing", "transit", "supplier"): "in_refund",
("outgoing", "transit", "customer"): "out_invoice",

}`

The dropshipping case is missing here.

("incoming", "supplier", "customer"): "in_invoice",