feat: disable automatic key retrieval during GPG encryption

Add the --no-auto-key-retrieve flag to prevent GPG from trying to fetch the key during encryption:

Author: chris2k20

imapbackup.py

@@ -369,6 +369,7 @@ def encrypt_file_gpg(input_file, recipient):
             '--batch',
             '--yes',
             '--trust-model', 'always',
+            '--no-auto-key-retrieve',  # Prevent GPG from trying to fetch keys during encryption
             '--encrypt',
             '--recipient', recipient,
             '--output', output_file,