chore(deps): update dependency element-hq/synapse to v1.123.0 (#667)

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

Author: renovate[bot]

synapse_rock/rockcraft.yaml

@@ -110,7 +110,7 @@ parts:
     plugin: nil
     source: https://github.com/element-hq/synapse/
     source-type: git
-    source-tag: v1.122.0
+    source-tag: v1.123.0
     build-environment:
       - RUST_VERSION: "1.76.0"
       - POETRY_VERSION: "1.7.1"