📝 docs(smolvlm): fix variable name in batch inference example (#42123)
Fixed incorrect variable name on line 162. The code creates a list called
'conversations' (plural) but incorrectly references 'conversation' (singular)
in the apply_chat_template call, which would cause a NameError.
This fixes the batch mixed media inference example to use the correct
variable name, allowing the code to run without errors.