Add sleep to mitigate pipeline timing issues

This patch should help to remove issues with timing. E.g. when the
container isn't fully started yet, but the request is already landing.

.gitlab-ci.yml

@@ -32,9 +32,11 @@ testing:
     - rm "$CONTAINER_FILE"
   script:
     - podman run -d -p 8053:8053 --cidfile="$CONTAINER_FILE" "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
+    - sleep 3
     - curl http://localhost:8053/dns-query\?name\=ci-test.dns.shivering-isles.com\&type\=A 2>/dev/null | jq '.Answer[].data' | grep -q '"127.0.0.123"'
     - 'podman stop "$(cat "$CONTAINER_FILE")" && podman rm "$(cat "$CONTAINER_FILE")" && rm "$CONTAINER_FILE"'
     - podman run -d -p 8053:8053 --cidfile="$CONTAINER_FILE" -e UPSTREAM_NAME="ci-upstream.dns.shivering-isles.com" "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
+    - sleep 3
     - curl http://localhost:8053/dns-query\?name\=ci-test.dns.shivering-isles.com\&type\=A 2>/dev/null | jq '.Answer[].data' | grep -q '"127.0.0.123"'
     - 'podman stop "$(cat "$CONTAINER_FILE")" && podman rm "$(cat "$CONTAINER_FILE")" && rm "$CONTAINER_FILE"'