fix: add gosu to hermes + ssh host key to honcho builder

Hermes: install gosu package so run-multi-gateways.sh's gosu hermes
drop works when USER hermes is set in Dockerfile.

Honcho: add openssh-client + ssh-keyscan to openconcho-builder stage
so SSH host key verification passes during Gitea clone on first build.

ai/honcho/Dockerfile

@@ -30,7 +30,7 @@ RUN corepack enable && corepack prepare pnpm@latest --activate
 WORKDIR /app
 RUN apt-get update && apt-get install -y git openssh-client && rm -rf /var/lib/apt/lists/**
 
-ARG OPENCONCHO_SHA=3b5c3290b27201c966e9b5e575720c770ce595d2
+ARG OPENCONCHO_SHA=3b5c3293fc18d768dbe85285264a8d66c896bd81
 RUN mkdir -p -m 0700 ~/.ssh && ssh-keyscan -p 2222 code.lazyworkhorse.net >> ~/.ssh/known_hosts 2>/dev/null
 RUN --mount=type=ssh git clone --depth 1 ssh://git@code.lazyworkhorse.net:2222/gortium/openconcho.git /app && \
     git -C /app fetch --depth 1 origin ${OPENCONCHO_SHA} && \