Link OSS mcpiper with mcroutercore

Summary:
The public CMake target links mcpiper only with mcrouter_lib, but generated Memcache router sources in that library reference implementations owned by mcroutercore. Link mcpiper with mcroutercore, which already exposes mcrouter_lib as a public dependency, so the executable receives both layers without duplicating its link dependencies.

Without this dependency, the Ubuntu 26.04 Arm64 GCC 15 OSS link fails with unresolved symbols including FailoverRateLimiter, getTags, ConstShardHashFunc, RequestClass::kShadow, and logFailover.

Reviewed By: anidev

Differential Revision: D116535486

fbshipit-source-id: 06cdb36cc1af216093a285ecc472f78aeb9f9b5a

Author: mcfi

CMakeLists.txt

@@ -488,7 +488,7 @@ set(MCPIPER_SOURCES
 )
 
 add_executable(mcpiper ${MCPIPER_SOURCES})
-target_link_libraries(mcpiper PRIVATE mcrouter_lib)
+target_link_libraries(mcpiper PRIVATE mcroutercore)
 set_target_properties(mcpiper PROPERTIES
   RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin"
 )