Skip uninstalling conflicting LLVM in CI

In case this doesn't help, I'll try out more things and then squash.

.github/workflows/build.yml

@@ -94,10 +94,6 @@ jobs:
         run: |
           cargo fmt --all -- --check
 
-      - name: Uninstall Conflicting LLVM
-        run: |
-          brew uninstall llvm
-
       - name: Install Neovim
         run: |
           brew install neovim