ci: fix docker inspect template — main branch had the wrong SHA merged

PR #1 merged 9aa96c4, which still used `.NetworkSettings.IPAddress`. That
field is empty on modern Docker (the IP is under `.Networks.<name>.IPAddress`)
and the template exits non-zero, killing the sidecar step before any test
runs. The fix landed on the PR branch as 414be71 but wasn't in the merge.

Switch to the `range .NetworkSettings.Networks` form so we pick the first
non-empty IP regardless of which bridge docker attached the container to.

.github/workflows/ci.yml

@@ -40,7 +40,16 @@ jobs:
             -e POSTGRES_PASSWORD=postgres \
             -e POSTGRES_DB=postgres \
             postgres:16-alpine >/dev/null
-          PG_IP=$(docker inspect -f '{{.NetworkSettings.IPAddress}}' "$NAME")
+          # `.NetworkSettings.IPAddress` is empty (and template-parse errors) on
+          # modern Docker where the IP lives under `.Networks.<name>.IPAddress`.
+          # The range form picks the first non-empty IP across whatever network
+          # docker put the container on.
+          PG_IP=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' "$NAME")
+          if [ -z "$PG_IP" ]; then
+            echo "postgres has no reachable IP" >&2
+            docker inspect "$NAME" >&2
+            exit 1
+          fi
           echo "PG_CONTAINER=$NAME" >> "$GITHUB_ENV"
           echo "CM_TEST_DATABASE_URL=postgres://postgres:postgres@${PG_IP}:5432/postgres" >> "$GITHUB_ENV"
           for i in $(seq 1 30); do