fix(git)!: standardize `git pull --rebase` aliases (#11224)

BREAKING CHANGE: The alias `gup` for `git pull --rebase` and its derivatives
are replaced by `gpr` for standardization. This means the previous aliases will
no longer be available after a few months. Meanwhile, the original aliases are
still working, with a deprecation notice.
See https://github.com/ohmyzsh/ohmyzsh/blob/master/plugins/git/README.md#deprecated-aliases


for the full list of deprecated aliases.

Fixes #11104
Closes #11224

Co-authored-by: Marc Cornellà <marc@mcornella.com>