Remove deprecated `setup-repo` command from git/server.py
- [x] I have summed up the feature in concise words in the [Summary](#summary) section.
- [x] I have completely described the feature in the [Description](#description) section.
- [x] I have completed the [Blockers](#blockers) section.
### Summary
Remove deprecated `setup-repo` command from git/server.py
### Description
This command is deprecated and should be removed. Currently it's just throws warning and calls the `create-pkgbase` but it's deprecated for years.
### Blockers
Scripts which still use it should be updated but they got enough notification now.
issue