Add ca-certificates to Prosody config which allows it to validate s2s certs.

Config/Prosody/Dockerfile

@@ -8,7 +8,7 @@ FROM debian:trixie-slim
 ## Setup ##
 # System Dependencies
 RUN apt-get update && \
-		apt-get install -y prosody prosody-modules \
+		apt-get install -y prosody prosody-modules ca-certificates \
 								bash sudo htop \
 								vim