Rollback to CPM 0.40.0 (#789)

This is required to allow overrides to work with projects that have a custom source subdir value.

See #788 for more information.

Authors:
  - Robert Maynard (https://github.com/robertmaynard)

Approvers:
  - Bradley Dice (https://github.com/bdice)

URL: #789

rapids-cmake/cpm/detail/download.cmake

@@ -52,8 +52,8 @@ function(rapids_cpm_download)
   list(APPEND CMAKE_MESSAGE_CONTEXT "rapids.cpm.download")
 
   # When changing version verify no new variables needs to be propagated
-  set(CPM_DOWNLOAD_VERSION 0.40.2)
-  set(CPM_DOWNLOAD_MD5_HASH 4d51aa9dab6104fad39c5b7a692d5e1c)
+  set(CPM_DOWNLOAD_VERSION 0.40.0)
+  set(CPM_DOWNLOAD_MD5_HASH 6c9866a0aa0f804a36fe8c3866fb8a2c)
 
   if(NOT DEFINED CPM_DOWNLOAD_LOCATION)
     if(CPM_SOURCE_CACHE)