[BUG] [expanded=false] in role selector returns elements without aria-expanded attribute

[ozyx]

Context:

• Playwright Version: 1.25.2
• Operating System: MacOS
• Node.js version: 18
• Browser: Chromium
• Extra: [any specific details about your environment]

Describe the bug

In the ARIA treeitem role spec, it states:

Each parent node should include the aria-expanded attribute. It is set to false when closed true when open. End nodes should not have the aria-expanded attribute included as the presence of the attribute indicates to assistive technologies that the node is a parent.

However, when using a role selector role=treeitem[expanded=false], Playwright will match on treeitem elements that don't have the aria-expanded attribute (end nodes).

Example (our implementation of tree role, truncated a bit):

<div role="tree" aria-expanded="true" class="c-tree-and-search__tree c-tree">
  <div
    class="c-tree__item-h"
    style="left: -1000px; position: absolute; visibility: hidden"
  >
<!-- etc... -->
      <div
        role="treeitem"
        class="c-tree__item-h"
        aria-expanded="true"
        style="top: 0px; position: absolute; padding-left: 0px"
      >
      </div>
      <div
        role="treeitem"
        class="c-tree__item-h"
        aria-expanded="true"
        style="top: 26px; position: absolute; padding-left: 18px"
      >
      </div>
      <div
        role="treeitem"
        class="c-tree__item-h"
        style="top: 52px; position: absolute; padding-left: 36px"
      >
      </div>
      <div
        role="treeitem"
        class="c-tree__item-h"
        aria-expanded="false"
        style="top: 78px; position: absolute; padding-left: 36px"
      >
      </div>
    </div>
  </div>

Notice "End Node", which does not have aria-expanded attribute and should not match [aria-expanded=false]:

... is being matched by the selector: