chore(deps): update mattermost package dependencies

| datasource | package                                  | from   | to     |
| ---------- | ---------------------------------------- | ------ | ------ |
| helm       | mattermost-enterprise-edition            | 2.6.53 | 2.6.54 |
| docker     | mattermost/mattermost-enterprise-edition | 9.8.0  | 9.9.0  |

common/zarf.yaml

@@ -18,6 +18,6 @@ components:
         namespace: mattermost
         url: https://helm.mattermost.com
         gitPath: chart
-        version: 2.6.53
+        version: 2.6.54
         valuesFiles:
           - ../values/common-values.yaml

values/upstream-values.yaml

@@ -1,4 +1,4 @@
 mattermostApp:
   image:
     repository: mattermost/mattermost-enterprise-edition
-    tag: 9.8.0
+    tag: 9.9.0

zarf.yaml

@@ -34,7 +34,7 @@ components:
           - values/upstream-values.yaml
     images:
       - appropriate/curl:latest
-      - mattermost/mattermost-enterprise-edition:9.8.0
+      - mattermost/mattermost-enterprise-edition:9.9.0
 
   - name: mattermost
     required: true