Describe the bug
I was in the process of investigating another issue, and I think sphinx-tabs assets are not currently being removed from pages that they should be in v3.4.4. Here's the result of a debugging session:

As you can see, the path in context["css_files"] check here is not quite right. path is of type PosixPath, and the only thing contained in context["css_files"] are objects of type sphinx.builders.html._assets._CascadingStyleSheet. If I check the HTML built by sphinx, I can see that the tabs.css is included, confirming the bug:

I think what we want here is
if path.suffix == ".css" and path in [Path(f.filename) for f in context["css_files"]]:
Reproduce the bug
I've updated the minimal working example to use the most recent version of sphinx-tabs: https://github.com/peytondmurray/minimalsphinx/tree/per-page-css
List your environment
No response