SLATE package: make MPI and OpenMP a requirement (#44979)

Co-authored-by: gragghia <gragghia@BlackM3.local>

var/spack/repos/builtin/packages/slate/package.py

@@ -70,7 +70,7 @@ class Slate(CMakePackage, CudaPackage, ROCmPackage):
     # The runtime dependency on cmake is needed by the stand-alone tests (spack test).
     depends_on("cmake", type="run")
 
-    depends_on("mpi", when="+mpi")
+    depends_on("mpi")
     depends_on("intel-oneapi-mkl threads=openmp", when="+sycl")
     depends_on("blas")
     depends_on("blaspp ~cuda", when="~cuda")
@@ -105,6 +105,8 @@ class Slate(CMakePackage, CudaPackage, ROCmPackage):
     depends_on("rocsolver", when="+rocm")
 
     requires("%oneapi", when="+sycl", msg="slate+sycl must be compiled with %oneapi")
+    requires("+mpi", msg="MPI is required (use of the 'mpi' variant is deprecated)")
+    requires("+openmp", msg="OpenMP is required (use of the 'openmp' variant is deprecated)")
 
     cpp_17_msg = "Requires C++17 compiler support"
     conflicts("%gcc@:5", msg=cpp_17_msg)
@@ -136,10 +138,8 @@ def cmake_args(self):
 
         config = [
             "-Dbuild_tests=%s" % self.run_tests,
-            "-Duse_openmp=%s" % ("+openmp" in spec),
             "-DBUILD_SHARED_LIBS=%s" % ("+shared" in spec),
             backend_config,
-            "-Duse_mpi=%s" % ("+mpi" in spec),
         ]
         if "+cuda" in spec:
             archs = ";".join(spec.variants["cuda_arch"].value)