Try revert to LLVM 20 for Ubuntu

Author: IsaacShelton

.github/workflows/remoteBuild.yml

@@ -88,6 +88,7 @@ jobs:
         run: |
           # sudo apt-get update
           sudo apt-get install -y libcurl4-openssl-dev
+          eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"
           # brew install zstd
           brew install llvm@20
           brew ls -v zstd