t/Controller/Build/constituents.t: assert the response is valid JSON, dump if it isn't

Dependencies

• [2] TRPMSYL3 add api endpoint: /build/<id>/constituents
• [3] LNUINAZC JSON -> JSON::MaybeXS

Change contents

• replacement in t/Hydra/Controller/Build/constituents.t at line 39
  [2.2190]→[2.2190:2238](∅→∅)
  − my $data = decode_json($constituents->content);
  [2.2190]

  [2.2238]
  +

  + my $data;

  + my $valid_json = lives { $data = decode_json($constituents->content); };

  + ok($valid_json, "We get back valid JSON.");

  + if (!$valid_json) {

  + use Data::Dumper;

  + print STDERR Dumper $constituents->content;

  + }