Change contest config for required contest from comma separated string to YAML list of strings

1 job for require_contest_participation in 1 minute and 53 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
failed #2342
test

00:01:53

 
Name Stage Failure
failed
test Test

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warning: build failed, waiting for other jobs to finish...
error: aborting due to previous error

error: build failed
make: *** [Makefile:23: clippy] Error 101
Cleaning up file based variables
ERROR: Job failed: exit code 1