Update to CPM v0.38.5 (#460)

Update to CPM [v0.38.5](https://github.com/cpm-cmake/CPM.cmake/releases/tag/v0.38.5).

Authors:
  - Paul Taylor (https://github.com/trxcllnt)

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

URL: #460

rapids-cmake/cpm/detail/download.cmake

@@ -42,8 +42,8 @@ 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 0.35.6)
-  set(CPM_DOWNLOAD_MD5_HASH c15cd4b7f511bc625c92ee6580821726)
+  set(CPM_DOWNLOAD_VERSION 0.38.5)
+  set(CPM_DOWNLOAD_MD5_HASH c98d14a13dfd1952e115979c095f6794)
 
   if(CPM_SOURCE_CACHE)
     # Expand relative path. This is important if the provided path contains a tilde (~)