ci(integration): the run: shell is dash, not busybox (#3237)

The runner-facts step answered rule 81's check on its first run, and the
answer is the one the check itself warned about: `/bin/sh` resolves to
`/usr/bin/dash`, because ci-python is Debian-based. The constraint the
rule exists for is unchanged — dash has no /dev/tcp, no arrays, no
`[[ ]]` — but the shell has never been busybox, and this comment was
repeating the wrong name at the one place a reader would trust it.

Rule 81's own statement still says busybox; correcting it is a rulebook
edit and goes through propose -> approve -> apply.

.forgejo/workflows/ci.yml

@@ -304,8 +304,9 @@ jobs:
           PG_IP=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' "$PG")
           test -n "$PG_IP"
           export DATABASE_URL="postgresql+asyncpg://scribe:ci_integration@${PG_IP}:5432/scribe_test"
-          # Wait for Postgres to accept connections (busybox sh — the runner
-          # default — has no bash /dev/tcp, so use Python).
+          # Wait for Postgres to accept connections. The run: shell is dash
+          # (/bin/sh -> /usr/bin/dash on this Debian-based image, confirmed by
+          # the step above) — no bash /dev/tcp, so use Python.
           /opt/venv/bin/python - "$PG_IP" <<'PY'
           import socket, sys, time
           for _ in range(30):