boxlib: Add BL_USE_PARTICLES cmake var (#39660)

Set BL_USE_PARTICLES to 1, which should case boxlib build to include Particles classes
according to CMakeLists.txt.

This seems to fix #18172
The aforementioned error seems to occur in cmake phase while processing
CMakeLists.txt in Src/C_ParticleLib, and appears to be due to the
variable containing the list of src files for the add_library() call
being empty unless BL_USE_PARTICLES is set to 1.

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

@@ -32,6 +32,7 @@ def cmake_args(self):
         options.extend(
             [
                 "-DBL_SPACEDIM=%d" % int(spec.variants["dims"].value),
+                "-DBL_USE_PARTICLES=1",
                 "-DCMAKE_POSITION_INDEPENDENT_CODE:BOOL=ON",
                 "-DENABLE_FBASELIB=ON",
                 "-DCMAKE_C_COMPILER=%s" % spec["mpi"].mpicc,