Update Spack.yml

Author: AlysonStahl-NOAA

.github/workflows/Spack.yml

@@ -35,7 +35,7 @@ jobs:
         custom-recipe: spack/package.py
         use-repo-cache: false
         spack-compiler: gcc
-        use-common-build-cache: true
+        use-common-build-cache: false
         cache-spack-lock: false
         repo-cache-key-suffix: ${{ matrix.os }}-${{ matrix.variants }}-2