NoMethodError: undefined method `find' for nil:NilClass

Sentry Issue: GITLABCOM-F7P

NoMethodError: undefined method `find' for nil:NilClass
  app/models/concerns/cross_database_modification.rb:92:in `block in transaction'
    yield
  lib/gitlab/database/load_balancing/connection_proxy.rb:121:in `public_send'
    connection.public_send(...)
  lib/gitlab/database/load_balancing/connection_proxy.rb:121:in `block in write_using_load_balancer'
    connection.public_send(...)
  lib/gitlab/database/load_balancing/load_balancer.rb:127:in `block in read_write'
    yield connection
  lib/gitlab/database/load_balancing/load_balancer.rb:205:in `retry_with_backoff'
    return yield attempt # Yield the current attempt count
...
(117 additional frame(s) were not displayed)