Update dock.mau.dev/mautrix/discord Docker tag to v0.6.4

roles/custom/matrix-bridge-mautrix-discord/defaults/main.yml

@@ -9,7 +9,7 @@ matrix_mautrix_discord_container_image_self_build_repo: "https://mau.dev/mautrix
 matrix_mautrix_discord_container_image_self_build_branch: "{{ 'main' if matrix_mautrix_discord_version == 'latest' else matrix_mautrix_discord_version }}"
 
 # renovate: datasource=docker depName=dock.mau.dev/mautrix/discord
-matrix_mautrix_discord_version: v0.6.3
+matrix_mautrix_discord_version: v0.6.4
 
 # See: https://mau.dev/mautrix/discord/container_registry
 matrix_mautrix_discord_docker_image: "{{ matrix_mautrix_discord_docker_image_name_prefix }}mautrix/discord:{{ matrix_mautrix_discord_version }}"