Revert "Upgrade spdlog to 1.10.0 (#312)" (#323)

This reverts commit 4b079dc.

See rapidsai/rmm#1176 for details.

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

Approvers:
  - Ray Douglass (https://github.com/raydouglass)
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: #323

rapids-cmake/cpm/versions.json

@@ -32,7 +32,7 @@
       "git_tag" : "branch-${version}"
     },
     "spdlog" : {
-      "version" : "1.10.0",
+      "version" : "1.8.5",
       "git_url" : "https://github.com/gabime/spdlog.git",
       "git_tag" : "v${version}"
     },