Remove outdated HTTP status codes

See https://github.com/openHPI/codeocean/pull/1349#pullrequestreview-1091652523

lib/runner/strategy/poseidon.rb

@@ -34,8 +34,6 @@ class Runner::Strategy::Poseidon < Runner::Strategy
         else
           execution_environments
         end
-      when 404
-        raise Runner::Error::EnvironmentNotFound.new
       else
         handle_error response
     end
@@ -258,9 +256,6 @@ class Runner::Strategy::Poseidon < Runner::Strategy
         response_body = self.class.parse response
         websocket_url = response_body[:websocketUrl]
         websocket_url.presence || raise(Runner::Error::UnexpectedResponse.new('Poseidon did not send a WebSocket URL'))
-      when 400
-        Runner.destroy(@allocation_id)
-        self.class.handle_error response
       else
         self.class.handle_error response
     end

spec/lib/runner/strategy/poseidon_spec.rb

@@ -291,7 +291,6 @@ describe Runner::Strategy::Poseidon do
     end
 
     include_examples 'BadRequest (400) error handling'
-    include_examples 'BadRequest (400) destroys local runner'
     include_examples 'Unauthorized (401) error handling'
     include_examples 'Gone (410) error handling'
     include_examples 'InternalServerError (500) error handling'