Support /api/v1/series API in query rejection config

[yeya24]

Is your feature request related to a problem? Please describe. We have a blog post https://cortexmetrics.io/blog/2025/08/04/block-the-blast-how-query-rejection-protects-your-cortex-cluster/#matching-criteria that talks about blocking bad queries using query rejection configs.

However, query rejection only supports instant and range queries. It doesn't support series request despite the blog mentioned it support series request.

Describe the solution you'd like Support series request in Query rejection query frontend. https://github.com/cortexproject/cortex/blob/master/pkg/querier/tripperware/query_attribute_matcher.go#L26

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

[friedrichg]

blog post fixed in https://github.com/cortexproject/cortex/pull/7044