The `git restore` command was introduced in Git version 2.23.0, which
was released in August 2019. Even late Linux distributions do not
include this modern of a Git binary. For example, Ubuntu 19.10 as of Nov
26, 2019 only includes Git 2.20.1.
In order to run hack/update-vendor.sh on machines with Git <2.23.0, I've
modified the script to use `git reset .` instead of `git restore
--staged`.
Issue #2560
Running this script as-is fails as `git ci` is not a recognised
command. Fixed by referencing `git commit` explicitly; I guess it
works as it may be aliased.
Thomas George Hartland