Integration tests should use Helia for all tests

[vasco-santos]

Currently blob.test.js has tests for bitswap using Helia commented. This is because trying to run a new Helia node triggers runtime errors in Node that look like previous node did not finish running and still has control of some resource. Given integration.test.js does exactly same test (and uses blob under the hood), it is not critical to make use of Helia again, but would be great to have it