search_end_to_end_sharded_cluster and search_end_to_end_single_node

have the experimental tags and are being run on non experimental variants and we should add a linter check to make sure that cannot happen again.

We also need linting to prevent this from getting worse in the future. See here for another engineer accidentally making the problem worse.

We should also make sure that individual tasks (or non standard tags) can get added to variants that are not experimental.