When shadowing, end of contest not in sync with primary.

[johnbrvc]

Describe the issue:
When shadowing, it is possible that PC2 will mark runs as DELeted even though they are valid.

To Reproduce:
Hard to reproduce reliably, but we have seen it at during WF system tests, and the NAC2024 real contest.
See the behavior sections below for a description.

Expected behavior:
PC2 should accept submissions without marking them as DEL until a END Contest state is received from the primary. Currently, it is possible that PC2's contest clock runs out a split second before the END state change is seen from the primary. This causes PC2 to think the contest is over prematurely, and, as a result, some runs may be marked as DEL and have to be hand-edited.

Actual behavior:
Submissions at the end of a contest come in very quickly right up until the buzzer. As a result, PC2 may think the contest is over (its contest clock has finished) before the notification from the primary indicating contest stop. The primary should be the authoritative clock for a contest. (State messages on the event feed).

Environment:
All

Log Info:

Screenshots:

Additional context: