cmake: drop c-ares::c-ares alias

Remove the c-ares::c-ares alias that was causing build failures after
bumping the minimum CMake version:

```
CMake Error at cmake/modules/Findc-ares.cmake:34 (add_library):
  add_library cannot create ALIAS target "c-ares::c-ares" because another
  target with the same name already exists.
Call Stack (most recent call first):
  src/CMakeLists.txt:463 (_find_package)
  src/seastar/cmake/SeastarDependencies.cmake:136 (find_package)
  src/seastar/CMakeLists.txt:395 (seastar_find_dependencies)`
```

The alias was originally added for backward compatibility with Seastar,
but is no longer needed since the updated Seastar submodule no longer
references the c-ares::c-ares target.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>

diff --git a/cmake/modules/Findc-ares.cmake b/cmake/modules/Findc-ares.cmake
index 93554ed2814602aa2f62027f09e2ce0e69e5ba96..0e4fcd580127f59540eb30621c38da1e29697678 100644 (file)
--- a/cmake/modules/Findc-ares.cmake
+++ b/cmake/modules/Findc-ares.cmake
@@ -30,9 +30,6 @@ if(c-ares_FOUND)
       IMPORTED_LOCATION "${c-ares_LIBRARY}")
   endif()
 
-  # to be compatible with old Seastar
-  add_library(c-ares::c-ares ALIAS c-ares::cares)
-
   if(NOT TARGET c-ares::c-ares)
     add_library(c-ares::c-ares ALIAS c-ares::cares)
   endif()