[PATCH] proxy-auth: additional tests

[PATCH] proxy-auth: additional tests

Also eliminate the special handling for socks proxy match.

Closes #20837

Backported-by: Samuel Henrique <samueloph@debian.org>
 * Refresh patch context for lib/url.c

Backported by: Samuel Henrique <samueloph@debian.org>
 * Bookworm 7.88.1: same proxy_info_matches and
   socks_proxy_info_matches functions, just at line 863. Bookworm's
   proxy_info_matches still uses strcasecompare() (upstream switched
   to curl_strequal() at some point post-7.88.1), so leave that
   call alone -- only add the new Curl_timestrcmp() user/passwd
   check inside it. Keep socks_proxy_info_matches() in place and
   switch the call site at line 1214 from socks_proxy_info_matches
   to proxy_info_matches, matching the trixie minimal-diff approach.
 * Drop the tests/http/test_13_proxy_auth.py and
   tests/http/testenv/curl.py hunks: bookworm has no tests/http/
   pytest infrastructure at all (those tests appeared in upstream
   later than 7.88.1).

Gbp-Pq: Name CVE-2026-3784.patch