Enable ignoring tags

Currently, this action fails if tag validation fails, including if the most recent tag is not a valid SemVer version. We should add a configurable tag ignore list, probably via an action input, maybe using globs.

Start by tracing where tag validation is implemented and how action inputs are declared. Define the ignore-list input and its matching behavior, then verify that ignored tags no longer cause validation failure while other invalid tags still do; the payload names no specific files or tests.

Written by the indexing model from the issue text.