Update matrixdotorg/mjolnir Docker tag to v1.8.3 (#3570)

* Update matrixdotorg/mjolnir Docker tag to v1.8.1

* Upgrade Mjolnir to v1.8.3

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Slavi Pantaleev <slavi@devture.com>

roles/custom/matrix-bot-mjolnir/defaults/main.yml

@@ -5,7 +5,7 @@
 matrix_bot_mjolnir_enabled: true
 
 # renovate: datasource=docker depName=matrixdotorg/mjolnir
-matrix_bot_mjolnir_version: "v1.7.0"
+matrix_bot_mjolnir_version: "v1.8.3"
 
 matrix_bot_mjolnir_container_image_self_build: false
 matrix_bot_mjolnir_container_image_self_build_repo: "https://github.com/matrix-org/mjolnir.git"