Lambda may not be necessary

[codacy-production]

Codacy detected an issue:

Message: Lambda may not be necessary

Occurred on:

• Commit: ffbeebd
• File: src/aijack/defense/paillier/fed_wrapper.py
• LineNum: 16
• Code: np.vectorize(lambda x: pk.encrypt(x))(grad.detach().numpy())

Currently on:

• Commit: f65f82b
• File: src/aijack/defense/paillier/fed_wrapper.py
• LineNum: 25