fix: replaced hardcoded redirectUri (#73)

## Description

This fixes a hardcoded redirect uri

## Related Issue

Fixes #
<!-- or -->
Relates to #

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Other (security config, docs update, etc)

## Checklist before merging

- [ ] Test, docs, adr added or updated as needed
- [ ] [Contributor Guide
Steps](https://github.com/defenseunicorns/uds-package-mattermost/blob/main/CONTRIBUTING.md#developer-workflow)
followed

---------

Co-authored-by: Michael-Kruggel <[email protected]>
Co-authored-by: Micah Nagel <[email protected]>

chart/templates/uds-package.yaml

@@ -9,7 +9,7 @@ spec:
     - name: Mattermost Login
       clientId: uds-swf-mattermost
       redirectUris:
-        - "https://chat.uds.dev/*"
+        - "https://{{ .Values.subdomain }}.{{ .Values.domain }}/*"
       defaultClientScopes:
         - "openid"
         - "mapper-oidc-username-username"