Integrations: Remove TimescaleDB

timescale/promscale has been discontinued.
See timescale/promscale#1836

Signed-off-by: beorn7 <[email protected]>

Author: beorn7

content/docs/operating/integrations.md

@@ -56,7 +56,6 @@ data volumes.
   * [M3DB](https://m3db.io/docs/integrations/prometheus/): read and write
   * [New Relic](https://docs.newrelic.com/docs/set-or-remove-your-prometheus-remote-write-integration): write
   * [OpenTSDB](https://github.com/prometheus/prometheus/tree/main/documentation/examples/remote_storage/remote_storage_adapter): write
-  * [PostgreSQL/TimescaleDB](https://github.com/timescale/promscale): read and write
   * [QuasarDB](https://doc.quasardb.net/master/user-guide/integration/prometheus.html): read and write
   * [SignalFx](https://github.com/signalfx/metricproxy#prometheus): write
   * [Splunk](https://github.com/kebe7jun/ropee): read and write