Update Helm chart docs and yaml (#11800)

**What this PR does / why we need it**:
Following recent loki `v2.9.4` and GEL `v1.8.6` patch releases, updates
Helm chart docs and yaml.

Loki release drone creates is the [PR as
expected](https://github.com/grafana/loki/pull/11769/files), but there
seems to be a problem with the GEL drone generating the docs -which is
looked at separately.
Instead I manually updated them in one go.

docs/sources/setup/install/helm/reference.md

@@ -856,7 +856,7 @@ false
 			<td>string</td>
 			<td></td>
 			<td><pre lang="json">
-"v1.8.4"
+"v1.8.6"
 </pre>
 </td>
 		</tr>

production/helm/loki/CHANGELOG.md

@@ -15,6 +15,7 @@ Entries should include a reference to the pull request that introduced the chang
 
 ## 5.42.0
 
+- [CHANGE] Changed versions of Loki v2.9.4 and GEL v1.8.6
 - [ENHANCEMENT] Bumped "grafana-agent-operator" depenency chart version to it's latest version
 
 ## 5.41.8

production/helm/loki/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 name: loki
 description: Helm chart for Grafana Loki in simple, scalable mode
 type: application
-appVersion: 2.9.3
+appVersion: 2.9.4
 version: 5.42.0
 home: https://grafana.github.io/helm-charts
 sources:

production/helm/loki/README.md

@@ -1,6 +1,6 @@
 # loki
 
-![Version: 5.42.0](https://img.shields.io/badge/Version-5.42.0-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 2.9.3](https://img.shields.io/badge/AppVersion-2.9.3-informational?style=flat-square)
+![Version: 5.42.0](https://img.shields.io/badge/Version-5.42.0-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 2.9.4](https://img.shields.io/badge/AppVersion-2.9.4-informational?style=flat-square)
 
 Helm chart for Grafana Loki in simple, scalable mode
 

production/helm/loki/values.yaml

@@ -376,7 +376,7 @@ enterprise:
   # Enable enterprise features, license must be provided
   enabled: false
   # Default verion of GEL to deploy
-  version: v1.8.4
+  version: v1.8.6
   # -- Optional name of the GEL cluster, otherwise will use .Release.Name
   # The cluster name must match what is in your GEL license
   cluster_name: null