Revert "[Backport staging-25.11] c-ares: fix IPv6 link-local DNS server support"

[mdaniels5757]

Reverts #462883

This change broke c-ares, because it was updated to version 1.34.6 in #472260. The patch that the PR that this is reverting (c-ares/c-ares@0fbeb87) is included in version 1.34.6.

Log of `nix-build -A c-ares` on staging-25.11 at e39fe06:

these 5 derivations will be built:
  /nix/store/4qsrp0wl6v8h6y772d8qz95f35ci0615-c-ares-1.34.6.drv
  /nix/store/y13fv4fzbj49x43a3fqzljdxn9dgh354-nghttp2-1.67.1.drv
  /nix/store/lfmsvfwal2am8j0zds5zjhgj1hdp7bja-curl-8.17.0.drv
  /nix/store/959s4sy1hmb7pj37ml92xbi0xv359aqz-cmake-4.1.2.drv
  /nix/store/98rd1jf012yc8smyshn8i5zvzc9hvq22-c-ares-1.34.6.drv
building '/nix/store/4qsrp0wl6v8h6y772d8qz95f35ci0615-c-ares-1.34.6.drv'...
Running phase: unpackPhase
unpacking source archive /nix/store/p8k4d8a43zbyls37b568x9zzd84z3hq9-c-ares-1.34.6.tar.gz
source root is c-ares-1.34.6
setting SOURCE_DATE_EPOCH to timestamp 1765210914 of file "c-ares-1.34.6/include/ares_build.h"
Running phase: patchPhase
applying patch /nix/store/2wsz0v0v1cqyyz6rzya8lg8cqz6gkbwl-fix-link-local-dns-servers.patch
patching file src/lib/ares_init.c
Reversed (or previously applied) patch detected!  Assume -R? [n]
Apply anyway? [n]
Skipping patch.
2 out of 2 hunks ignored -- saving rejects to file src/lib/ares_init.c.rej
patching file src/lib/ares_set_socket_functions.c
patch unexpectedly ends in middle of line
Reversed (or previously applied) patch detected!  Assume -R? [n]
Apply anyway? [n]
Skipping patch.
1 out of 1 hunk ignored -- saving rejects to file src/lib/ares_set_socket_functions.c.rej
error: Cannot build '/nix/store/4qsrp0wl6v8h6y772d8qz95f35ci0615-c-ares-1.34.6.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/fqvmch37hps31bv5yx1cj5k8fkqp13kx-c-ares-1.34.6-man
         /nix/store/g2npabk27mrqfghrgni8ljql9qys4d5n-c-ares-1.34.6
         /nix/store/ghsyrii1z17bdypkry3y5c6y7i5i1r4k-c-ares-1.34.6-dev
       Last 17 log lines:
       > Running phase: unpackPhase
       > unpacking source archive /nix/store/p8k4d8a43zbyls37b568x9zzd84z3hq9-c-ares-1.34.6.tar.gz
       > source root is c-ares-1.34.6
       > setting SOURCE_DATE_EPOCH to timestamp 1765210914 of file "c-ares-1.34.6/include/ares_build.h"
       > Running phase: patchPhase
       > applying patch /nix/store/2wsz0v0v1cqyyz6rzya8lg8cqz6gkbwl-fix-link-local-dns-servers.patch
       > patching file src/lib/ares_init.c
       > Reversed (or previously applied) patch detected!  Assume -R? [n]
       > Apply anyway? [n]
       > Skipping patch.
       > 2 out of 2 hunks ignored -- saving rejects to file src/lib/ares_init.c.rej
       > patching file src/lib/ares_set_socket_functions.c
       > patch unexpectedly ends in middle of line
       > Reversed (or previously applied) patch detected!  Assume -R? [n]
       > Apply anyway? [n]
       > Skipping patch.
       > 1 out of 1 hunk ignored -- saving rejects to file src/lib/ares_set_socket_functions.c.rej
       For full logs, run:
         nix log /nix/store/4qsrp0wl6v8h6y772d8qz95f35ci0615-c-ares-1.34.6.drv
error: Cannot build '/nix/store/y13fv4fzbj49x43a3fqzljdxn9dgh354-nghttp2-1.67.1.drv'.
       Reason: 1 dependency failed.
       Output paths:
         /nix/store/64y0iqz8kvbwxf6cnv6xikbrk30gm828-nghttp2-1.67.1-man
         /nix/store/b8sk13nbpxsa6pjn5szjccayyrjxmbld-nghttp2-1.67.1-dev
         /nix/store/fq10b8zbiha35zp9rbja7xl6b7djmnfd-nghttp2-1.67.1-lib
         /nix/store/jvhi9hj27pr4p97k3snjhmhm4yhvsfw8-nghttp2-1.67.1
         /nix/store/s39x36k7qpflxgblc6r59z5r7r2w5yhy-nghttp2-1.67.1-doc
error: Cannot build '/nix/store/lfmsvfwal2am8j0zds5zjhgj1hdp7bja-curl-8.17.0.drv'.
       Reason: 1 dependency failed.
       Output paths:
         /nix/store/1xl6d7hpxwsxxgil2p0cw4i3svvcv6gd-curl-8.17.0-man
         /nix/store/43ywc71sc8x7lj9m4hnx6yrc2dyrlz94-curl-8.17.0
         /nix/store/4pfyhqkhs7lgpdxdbn7yslj4jmxjphax-curl-8.17.0-debug
         /nix/store/laa0rdv82irfyxw3dy1shhjyzv0xj2r5-curl-8.17.0-bin
         /nix/store/qpy6vy5sjkslhcxplay4mxjk7fw9rxds-curl-8.17.0-devdoc
         /nix/store/vslyfrb33r7crrcmqcfd57l8q9jghzks-curl-8.17.0-dev
error: Cannot build '/nix/store/959s4sy1hmb7pj37ml92xbi0xv359aqz-cmake-4.1.2.drv'.
       Reason: 1 dependency failed.
       Output paths:
         /nix/store/40k9xg64443ipgbaiwfpvz1lqzxyc26n-cmake-4.1.2
         /nix/store/5q9pblg9wk9l4b0d86gmfzax5j6zvdd0-cmake-4.1.2-debug
error: Cannot build '/nix/store/98rd1jf012yc8smyshn8i5zvzc9hvq22-c-ares-1.34.6.drv'.
       Reason: 1 dependency failed.
       Output paths:
         /nix/store/7lhxz6kbb1ydandd587bf4hfi0697m4x-c-ares-1.34.6
         /nix/store/9bjmmdf2gx4ja7s0fdkvhkl038mralwz-c-ares-1.34.6-man
         /nix/store/mz4i7jqcfx5f8xkl558d1z174kz04mrw-c-ares-1.34.6-dev

It's a revert, not a cherry-pick.

[mdaniels5757]

c-ares.passthru.tests succeed at HEAD (which is based atop the latest staging-25.11) on x86_64-linux. Let's do this.