Do not auto-enable Valkey when Element Call is enabled

Not sure why we were doing this.

LiveKit Server may utilize Valkey, but we don't configure it this way,
so there's no need to do it.

group_vars/matrix_servers

@@ -4537,7 +4537,7 @@ ntfy_visitor_request_limit_exempt_hosts_hostnames_auto: |
 #
 ######################################################################
 
-valkey_enabled: "{{ matrix_synapse_workers_enabled or (matrix_hookshot_enabled and matrix_hookshot_encryption_enabled) or matrix_element_call_enabled }}"
+valkey_enabled: "{{ matrix_synapse_workers_enabled or (matrix_hookshot_enabled and matrix_hookshot_encryption_enabled) }}"
 
 valkey_identifier: matrix-valkey