Update spack_build.yml

Author: Cameron Rutherford

.github/workflows/spack_build.yml

@@ -118,9 +118,7 @@ jobs:
           submodules: true
 
       - name: Clone Spack
-        run: |
-          git clone https://github.com/spack/spack.git
-          popd
+        run: git clone https://github.com/spack/spack.git
 
       - name: Setup Spack
         run: echo "$PWD/spack/bin" >> "$GITHUB_PATH"