Update docker.io/moonrailgun/tianji Docker tag to v1.20.6

No problems upgrading the Docker container with a Docker compose yaml file within Portainer and by means of Portainer DevOps resp. GitOps with dependency update facilitated by Mend's Renovate Bot.

This MR contains the following updates:

Package	Update	Change
docker.io/moonrailgun/tianji	patch	`1.20.4` -> `1.20.6`

Release Notes

msgbyte/tianji (docker.io/moonrailgun/tianji)

`v1.20.6`

Compare Source

Bug Fixes

restore timezone parameter in insights functions to improve date handling (d3ee48e)

`v1.20.5`

Compare Source

Bug Fixes

fix a issue which maybe cause service crash (08f3fe5)
make timezone parameter optional in date-related functions (e05a289)

Others

remove sitemap (357c11c)
update docusaurus dependencies to version 3.7.0 and enable sitemap configuration (681d50c)