Use distinct to return unique product list for scope visible_for

[jibees]

What? Why?

Product were displayed twice (or more) in certain condition under order cycle incoming products admin interface

Closes #7885

What should we test?

1. Create a product with n variants, with n > 1
2. Add it to the inventory
3. Add it to an OC
4. Under "Advanced Settings" choose the option "Coordinators inventory only"
5. See this product appears 1 time in the incoming section of the OC -> notice the loaded variant count is also correct (xx / yy Variants Loaded where xx < yy)

Release notes

Remove duplicate product under incoming products section of an order cycle under certain conditions

Changelog Category: User facing changes

[mkllnk]

No spec?

A unit test in the product_spec.rb file would be enough, I think.

[jibees]

No spec?

A unit test in the product_spec.rb file would be enough, I think.

Right: fff2c3a !

[mkllnk]

😄

[filipefurtad0]

Hey @jibees ,

Before this PR the behavior is as described in #7885:

After this PR, OC which should show inventory only variants appear correctly:

Regression tested:

• adding variants to OC with "all products" option selected
• adding variants to OC with "coordinator's inventory only"
• checked whether these appear as expected in the shop front

All good, good to go 👍