We need to remove the Sphinx HTML docs

[Gerald Pfeifer]

On Sat, 26 Apr 2025, Jonathan Wakely wrote:
> $ grep -R  'generator.*Docutils' libgomp | wc -l
> 136
> $ grep -R  'generator.*Docutils' libitm | wc -l
> 8
> $ grep -R  'generator.*Docutils' gdc | wc -l
> 7
> $ grep -R  'generator.*Docutils' gfc-internals | wc -l
> 4

I yanked all these, including

  _sources/ 
  searchindex.js
  objects.inv 

in each of these subdirectories - further leftovers from Sphinx.

Similarly I removed gdc/invoking-gdc/, 
gfc-internal/generating-the-intermediate-language-for-later-stages/ ,
and a couple of similiar subdirectories under libgomp/ where docs were 
generated/stored.

Clearly the issue is how we generate and then copy docs on the server, 
which is incremental instead of replacing what is there (and removing old 
stuff).

Gerald