Enable CI for macOS LLVM 14 (rust-lang#711)

Author: tgymnich

.github/workflows/enzyme-ci.yml

@@ -60,13 +60,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        llvm: ["8", "9", "11", "12", "13"] #, "14"]
+        llvm: ["8", "9", "11", "12", "13", "14"]
         build: ["Release", "Debug"] # "RelWithDebInfo"
 
     timeout-minutes: 30 
     steps:
     - name: add llvm 
       run: |
+          brew update
           brew install llvm@${{ matrix.llvm }} autoconf make cmake gcc libtool
           sudo python3 -m pip install --upgrade pip setuptools
           sudo python3 -m pip install lit