bug: added safeguards to get_module_name

Added safeguards to ensure cp and jnp are reached only if installed.

Author: mrava87

pylops/utils/backend.py

@@ -114,9 +114,9 @@ def get_module_name(mod: ModuleType) -> str:
     """
     if mod == np:
         backend = "numpy"
-    elif mod == cp:
+    elif deps.cupy_enabled and mod == cp:
         backend = "cupy"
-    elif mod == jnp:
+    elif deps.jax_enabled and mod == jnp:
         backend = "jax"
     else:
         raise ValueError("module must be numpy, cupy, or jax")