devel/viewvc-devel: update to 1.3.0-20250316

Recently ViewVC 1.3.0-devel had fixed an issue for using vcauth submodule on
Python >= 3.12. [1][2].

Also there are some minor fixes since 1.3.0-20231018, including improvement
of htpasswd support for standalone server[3] and new "image view" feature[4].

[1] https://github.com/viewvc/viewvc/issues/367
[2] https://github.com/viewvc/viewvc/pull/368
[3] https://github.com/viewvc/viewvc/pull/362
[4] https://github.com/viewvc/viewvc/pull/364

PR: 285581