MM-53962: Adding ES8 dependency (#24399)

* Adding ES8 dependency

```release-note
NONE
```


Co-authored-by: Mattermost Build <build@mattermost.com>

server/build/docker-compose-generator/main.go

@@ -31,6 +31,7 @@ func main() {
 		"inbucket":           9001,
 		"openldap":           389,
 		"elasticsearch":      9200,
+		"opensearch":         9201,
 		"dejavu":             1358,
 		"keycloak":           8080,
 		"prometheus":         9090,