build: specify POST_BUILD when using add_custom_command

This is needed specifically for the second signature of
add_custom_command, which appends an operation to an existing target.
This will prevent the cmake warning CMP0175.

Reference: https://cmake.org/cmake/help/latest/policy/CMP0175.html

cmake/Util.cmake

@@ -61,6 +61,7 @@ function(add_glob_target)
   if(NOT ARG_COMMAND)
     add_custom_target(${ARG_TARGET})
     add_custom_command(TARGET ${ARG_TARGET}
+      POST_BUILD
       COMMAND ${CMAKE_COMMAND} -E echo "${ARG_TARGET} SKIP: ${ARG_COMMAND} not found")
     return()
   endif()

src/nvim/CMakeLists.txt

@@ -750,6 +750,7 @@ add_custom_target(nvim_runtime_deps)
 if(WIN32)
   # Copy DLLs and third-party tools to bin/ and install them along with nvim
   add_custom_command(TARGET nvim_runtime_deps
+    POST_BUILD
     COMMAND ${CMAKE_COMMAND} -E ${COPY_DIRECTORY} ${PROJECT_BINARY_DIR}/windows_runtime_deps/
       ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
   install(DIRECTORY ${PROJECT_BINARY_DIR}/windows_runtime_deps/
@@ -791,7 +792,10 @@ file(MAKE_DIRECTORY ${BINARY_LIB_DIR})
 
 # install treesitter parser if bundled
 if(EXISTS ${DEPS_PREFIX}/lib/nvim/parser)
-  add_custom_command(TARGET nvim_runtime_deps COMMAND ${CMAKE_COMMAND} -E ${COPY_DIRECTORY} ${DEPS_PREFIX}/lib/nvim/parser ${BINARY_LIB_DIR}/parser)
+  add_custom_command(
+    TARGET nvim_runtime_deps
+    POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E ${COPY_DIRECTORY} ${DEPS_PREFIX}/lib/nvim/parser ${BINARY_LIB_DIR}/parser)
 endif()
 
 install(DIRECTORY ${BINARY_LIB_DIR}