Docs: additional caching documentation (#31925)

* Update query-caching.md

* Update enterprise-configuration.md

Co-authored-by: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

docs/sources/enterprise/enterprise-configuration.md

@@ -345,3 +345,9 @@ Setting 'enabled' to true enables caching datasource queries for all data source
 ### ttl
 
 The default TTL (time to live) if no other TTL is available.
+
+## [caching.memory]
+
+### gc_interval
+
+When storing cache data in-memory, this setting defines how often a background process cleans up stale data from the in-memory cache. More frequent "garbage collection" can keep memory usage from climbing but will increase CPU usage.

docs/sources/enterprise/query-caching.md

@@ -22,3 +22,7 @@ Query caching currently works for all backend data sources. You can enable the c
 ## Enable query caching
 
 To enable and configure query caching, please refer the the [Query caching section of Enterprise Configuration]({{< relref "./enterprise-configuration.md#query-caching" >}}).
+
+## Sending a request without cache
+
+If the data source query request contains an `X-Cache-Skip` header, then Grafana skips the caching middleware, and does not search the cache for a response. This can be particularly useful when debugging data source queries using cURL.