update shoutrrr to v0.8+ for telegram message_thread_id support

[99red]

Please describe your feature request:

Update v0.7.1 shoutrrr dependency to v0.8 in go.mod

Describe the use case of this feature:

shoutrrr v0.8 adds the message_thread_id parameter to the telegram provider allowing to post messages to specific channel topics instead of just the specified channel via the telegram_chat_id:<channel_id>:<topic_id> format.

Relevant shoutrrr commit: https://github.com/containrrr/shoutrrr/commit/04c6ea804c9ca7e410834cdd54460737fce10414