message: fix(shell-api): further relax PlanCache integration test
  I was sloppy in and should have reduced this further
  so that the tests actually pass.
diff: @@ -2005,13 +2005,11 @@ describe('Shell API (integration)', function() {
  await loadQueryCache(collection);
  const planCache = collection.getPlanCache();
  const res = await planCache.list([{ $project: { queryHash: 1 } }]);
  - expect(res).to.deep.equal([
  - // We do not test for the exact query hashes here, as they can vary between
  - // server versions. Hashes for queries 3 and 4 are always equal currently.
  - { queryHash: `${res[0].queryHash}` },
  - { queryHash: `${res[1].queryHash}` },
  - { queryHash: `${res[2].queryHash}` },
  - { queryHash: `${res[2].queryHash}` }
  + // The 6.0 server greatly reduces the expectations we can make here,
  + // so just assert that query hashes are returned.
  + expect(res).to.have.lengthOf(4);
  + expect(res.map(doc => Object.keys(doc))).to.deep.equal([
  + ['queryHash'], ['queryHash'], ['queryHash'], ['queryHash']
  ]);
  });
  });
  