[BUG]Having "*" in authorized_imports does not actually allow you to use any import

[CalOmnie]

Describe the bug
Having "*" in authorized_imports does not matter in get_safe_module

Code to reproduce the error
The simplest code snippet that produces your bug.

from smolagents import CodeAgent, HfApiModel
model = HfApiModel()
agent = CodeAgent(model=model, additional_authorized_imports=["*"], tools=[])
code = """
import os
print(os.getcwd)
"""
agent.run(f"Run the following code: {code}")

Error logs (if any)

Expected behavior
I should be able to run the example when using "*"

Packages version:
Run pip freeze | grep smolagents and paste it here.
1.8.0

Additional context
Add any other context about the problem here.

[CalOmnie]

Tentative fix: #507