Force using old fmt in nvbench. (#12067)

This is a port of #12064 to 22.12 to unblock CI because forward mergers are currently disabled.

Authors:
  - Vyas Ramasubramani (https://github.com/vyasr)

Approvers:
  - GALI PREM SAGAR (https://github.com/galipremsagar)
  - Robert Maynard (https://github.com/robertmaynard)

URL: #12067

cpp/CMakeLists.txt

@@ -753,7 +753,10 @@ if(CUDF_BUILD_BENCHMARKS)
   include(${rapids-cmake-dir}/cpm/gbench.cmake)
   rapids_cpm_gbench()
 
-  # Find or install NVBench
+  # Find or install NVBench Temporarily force downloading of fmt because current versions of nvbench
+  # do not support the latest version of fmt, which is automatically pulled into our conda
+  # environments by mamba.
+  set(CPM_DOWNLOAD_fmt TRUE)
   include(${rapids-cmake-dir}/cpm/nvbench.cmake)
   rapids_cpm_nvbench()
   add_subdirectory(benchmarks)