Code Optimization and Issues Fixes in ComfyUI server

[programming-pupil]

Description

This PR addresses two issues in the ComfyUI server code:

1. Fixed parameter name in the get_embeddings route handler that would cause an unhandled exception
2. Remove the redundant f.close() from the with open(...) as f: block

Changes

1. Changed parameter name from self to request in the /embeddings route
2. Remove the redundant f.close() from the with open(...) as f: block
   The with statement (context manager) is designed to ensure that resources (such as file handles) are properly freed at the end of a code block (e.g., by calling its exit method, which for file objects would normally call close()). So f.close() is not necessary in this case

Testing Done

Verified that:

1. The /embeddings endpoint works correctly after the fix
2. File resources are properly managed in image comparison operations
3. No functionality has been broken by these changes