Rename spack env branch names in our script

The branch names in the repo spack-environments changed to use the format releases/dev-23a and for the spack fork, it was changed to mpsd/v0.19_dev-23a (see spack-environments!36 (merged) we dont worry about that in this script ) This MR updates those changes into our source.

src/mpsd_software_manager/mpsd_software.py

@@ -392,8 +392,9 @@ def get_available_package_sets(mpsd_release: str) -> List[str]:
     tmp_dir_path = Path(tmp_dir.name)
 
     # find package_sets by cloning repository and checking out right branch
+    brach_name = f"releases/{mpsd_release}"
     clone_repo(
-        tmp_dir_path, config_vars["spack_environments_repo"], branch=mpsd_release
+        tmp_dir_path, config_vars["spack_environments_repo"], branch=brach_name
     )
     # look for directories defining the package_sets