chore: add rc support for dependency updater (#909)

* chore: add rc support for dependency updater

* fix: skip unparseable versions in dependency updater

When the current tag couldn't be parsed (e.g., prefixed tag without
tagPrefix configured), the updater would allow any tag through,
potentially selecting tags from different products in the same repo.

Now unparseable tags are properly skipped in both validation and
max-version selection.

* remove tag