fix(dns): update c-ares to fix Windows DNS SRV regression

Updates c-ares to include the fix from c-ares/c-ares#1064 which
resolves the DNS SRV query failure on Windows introduced in v1.34.6.

The bug was in commit c-ares/c-ares@1d1b3d4a which changed Windows
registry reading to use wide strings but left an incorrect check
for empty string size (size == 1 instead of size == sizeof(WCHAR)).
This caused the DNS server list to be corrupted on Windows.

Fixes #25718

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

cmake/targets/BuildCares.cmake

@@ -4,7 +4,7 @@ register_repository(
   REPOSITORY
     c-ares/c-ares
   COMMIT
-    3ac47ee46edd8ea40370222f91613fc16c434853
+    e29bca8b113d4c5bbf2996f3e94fccbc298a4503
 )
 
 register_cmake_command(