The Git protocol specification states about `ls-refs`[^1]:
> ref-prefix <prefix>
> When specified, only references having a prefix matching one of
> the provided prefixes are displayed. Multiple instances may be
> given, in which case references matching any prefix will be
> shown. Note that this is purely for optimization; a server MAY
> show refs not matching the prefix if it chooses, and clients
> should filter the result themselves.
The `ref-prefix` arguments should not be relied on and post-filtering
after the ls-refs invocation should also be performed.
[^1]: https://git-scm.com/docs/protocol-v2#_ls_refs
8070f98a5b