Remove CI Discovery.yml Sync During Build Process

• remove the CI step https://gitlab.com/meltano/hub/-/blob/main/.gitlab-ci.yml#L42
• do a final refresh of the hub meltano optimized files using the splitter script https://gitlab.com/meltano/hub/-/blob/main/discovery_splitter.py, nothing should change but just in case
• remove the python script discovery_splitter script