Fix cmake-macos workflow

As mentioned in the install log, lld needs to be installed separately.

From log:
clang++: error: invalid linker name in argument '-fuse-ld=/opt/homebrew/opt/llvm/bin/ld64.lld'

.github/workflows/cmake-macos.yml

@@ -32,7 +32,7 @@ jobs:
         run: |
           export HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=1
           brew update --quiet
-          brew install --force --overwrite cmake llvm ninja lowdown
+          brew install --force --overwrite cmake llvm lld ninja lowdown
 
       - name: Configure
         run: |