fix: diff WC respecting internal DOM modifications

[aralroca]

Fixes brisa-build/brisa#611

The problem that happened is that when doing diffing of the WC made 2 steps, first, it made an insert (L176), and after adding the node, it entered in line 188 and made a diffing with the newNode when the insertedNode was already a clone of the new one, but of course, the new one did not have the internal change of the DOM modified by the WC (this.setAttribute), then it is as if it had not been applied.

https://github.com/aralroca/diff-dom-streaming/blob/0169dc1c9315099f340f7d60599e9fecf201eaca/src/index.ts#L173-L188

Example of WC:

class TestWC extends HTMLElement {
  connectedCallback() {
    this.setAttribute("data-connected", "true");
  }
}
customElements.define("test-wc", TestWC);

This PR fix the removal of data-connected in this extra unnecessary step.

Removing this code, all the tests continue passing and it solves the new tests that I have added.

CC: @AlbertSabate