Fix CI testing. (#120)

Author: jrood-nrel

.github/workflows/ci.yml

@@ -41,7 +41,7 @@ jobs:
             spack env activate e4s-build && \
             cd ${EXAWIND_MANAGER}/environments/e4s-build && \
             ln -s ${GITHUB_WORKSPACE} exawind && \
-            spack develop --no-clone exawind@=master && \
+            spack develop --no-modify-concrete-specs --no-clone exawind@=master && \
             spack concretize -f && \
             spack install && \
             spack cd -b exawind && \