git diff > patchfile
patch -p1 < patchfile
These are the two commands that help you to apply git diff patch without installing git.
The latest versions of patch command in version 2.7, support most features of the "diff --git" format, which includes renames and copies, permission changes, and symlink diffs.
So if you are using the latest version above 2.7 then you need to use the patch command and there is no need for the git.and able to apply its diff as a patch.