[MATRIX] Bump signal bridge to v0.7.3

https://www.swordarmor.fr/mautrix-signal-your-message-may-not-have-been-bridged-110-verification-failure-in-zkgroup.html

matrix/docker-compose.yml

@@ -48,7 +48,7 @@ services:
       - "co.elastic.logs/fileset=log"
 
   signal-bridge:
-    image: dock.mau.dev/mautrix/signal:latest
+    image: dock.mau.dev/mautrix/signal:v0.7.3
     restart: unless-stopped
     volumes:
       - ${DATA_PATH}/mautrix-signal:/data:z