Fix tournament match submission for byes

[ianpaschal]

Description

When submitting a match result for a bye, the user is required to still put in some value for the player or they will see the following error message:

Uncaught Match result must include reference to another user or a placeholder.

This is unintuitive since there is no other player.

A hot fix was created for Swedish Nationals in December 2025 rendering the Placeholder field, ensuring that the error can be silenced, but the correct solution is for no input to be required for the match result at all.