ENH: Disable unnecessary compression support in LLVM build configuration

CMake building of llvm autodetects zstd and zlib from homebrew and automatically links against them.

A compiler warning is given:

```
ld: warning: building for macOS-11.0, but linking with dylib '/opt/homebrew/opt/zstd/lib/libzstd.1.dylib' which was built for newer version 15.0
```

Additionally, this prevents castxml from running on many systems due to the dependence on homebrew being installed with the same or newer version as was present during compilation.

Author: hjmjohnson

CMakeLists.txt

@@ -95,6 +95,10 @@ else()
       -DLLVM_INCLUDE_DOCS:BOOL=OFF
       -DLLVM_ENABLE_OCAMLDOC:BOOL=OFF
       -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN:BOOL=ON
+      # Disable unneeded compression support in llvm
+      -DLLVM_USE_STATIC_ZSTD:BOOL=OFF
+      -DLLVM_ENABLE_ZLIB:BOOL=OFF
+      -DLLVM_ENABLE_ZSTD:BOOL=OFF
       ${osx_args}
     ${verbose_command}
     ${download_extract_timestamp_flag}