Fix issue with crash loops

Docker Compose starts the services with the executables as PID 1, which has special signal handling. Run the executables through tini for proper signal handling.

docker/alpine.Dockerfile

@@ -13,6 +13,7 @@ RUN --mount=type=cache,target=/var/cache/apk,sharing=locked \
     mariadb-connector-c \
     openssl \
     python3 \
+    tini \
     tzdata \
     zeromq \
     zlib

docker/ubuntu.Dockerfile

@@ -19,6 +19,7 @@ RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     libzmq5 \
     mariadb-client \
     python3 \
+    tini \
     tzdata \
     zlib1g
 

entrypoint.sh

@@ -11,4 +11,4 @@ export XI_NETWORK_SQL_PASSWORD
 export XI_NETWORK_SQL_LOGIN
 export XI_NETWORK_SQL_DATABASE
 
-exec "$@"
+exec /usr/bin/tini -- "$@"