When running collectstatic with a hashing static file storage backend,
URLs referencing other files were normalized with posixpath.normpath.
This could corrupt URLs: for example 'a.css#b/../c' became just 'c'.
Normalization seems to be an artifact of the historical implementation.
It contained a home-grown implementation of posixpath.join which relied
on counting occurrences of .. and /, so multiple / had to be collapsed.
The new implementation introduced in the previous commit doesn't suffer
from this issue. So it seems safe to remove the normalization.
There was a test for this normalization behavior but I don't think it's
a good test. Django shouldn't modify CSS that way. If a developer has
rendundant /s, it's mostly an aesthetic issue and it isn't Django's job
to fix it. Conversely, if the user wants a series of /s, perhaps in the
URL fragment, Django shouldn't destroy it.
Refs #26249.
A @font-face declaration may contain a fragment that looks like a relative path,
e.g. @font-face { src: url('../fonts/font.svg#../path/like/fragment'); }
In this case, an incorrect path was passed to the storage backend, which raised
an error that caused collectstatic to crash.
