prometheus_tsdb_head_stale_series

This release introduces new PromQL functions and experimental features for timestamp handling and histograms, alongside numerous performance improvements and bug fixes across discovery, TSDB, and the UI. API changes include deprecating certain `stats` query parameter values and enhancing the `/api/v1/status/config` endpoint.

This release introduces new PromQL functions like `start_timestamp`, enhances service discovery with OCI support, and includes numerous performance improvements and bug fixes across TSDB, scraping, and remote write functionalities. It also deprecates certain `stats` query parameter values for future removal.

This release introduces a new metric to monitor stale series within the TSDB Head block for improved observability.