Update ci.yml

Author: mcbarton

.github/workflows/ci.yml

@@ -613,7 +613,7 @@ jobs:
     - name: Build and Test/Install CppInterOp on Windows systems
       if: ${{ runner.os == 'windows' }}
       run: |
-        $env:LLVM_DIR="%cd\llvm-project"
+        $env:LLVM_DIR="%cd%\llvm-project"
         echo "LLVM_DIR=$env:LLVM_DIR"
         echo "LLVM_DIR=$env:LLVM_DIR" >> $env:GITHUB_ENV