Remove an entry for matrix-registration from setup.yml

Signed-off-by: Suguru Hirahara <did🔑z6MkvVZk1A3KBApWJXv2Ju4H14ErDfRGxh8zxdXSZ4vACDg5>

setup.yml

@@ -106,7 +106,6 @@
     - galaxy/prometheus
     - galaxy/grafana
     - custom/matrix-prometheus-services-connect
-    - custom/matrix-registration
     - custom/matrix-client-element
     - galaxy/hydrogen
     - galaxy/cinny