Downgrade windows to LLVM 14

Windows requires a patch to the Findzstd cmake file
(llvm/llvm-project@e7fc754)
which is available in LLVM 16, not LLVM 15.

Author: alexbaden

omniscidb/scripts/mapd-deps-conda-windows-env.yml

@@ -18,15 +18,15 @@ dependencies:
   - arrow-cpp  11.0
   - pyarrow    11.0
   - pandas     1.5.3
-  - llvmdev     15.*
+  - llvmdev     14.*
   - openjdk     17.*
   - tbb-devel
   - cython
   - make
   - fmt
   - maven
   - boost-cpp
-  - clangdev   15.*
+  - clangdev   14.*
   - llvm
   - double-conversion
   - snappy