[Tech debt]: remove skip opening auction

[gordsport]

Remove skip opening auction:

This code was originally added for unit testing, back when we had liquidity auctions still (not having to faff around setting up supplied stake, ensuring volume on either side of the book etc... in order to test stuff).

That code path was never meant to be executed when running normally, but clearly it's caused, or contributed to this issue.

• remove the skip opening auction code
• make sure all tests are passing