Add missing dependency to supervisor Containerfile

Without the `docker` package being installed, the supervisor is unable to start runs when deployed on a Docker platform.

Signed-off-by: Erin Allison <eallison@andrettikarting.com>

Author: erin-allison

apps/supervisor/Containerfile

@@ -9,7 +9,7 @@ RUN npx -q turbo@1.10.9 prune --scope=supervisor --docker
 
 FROM node-22-alpine AS base
 
-RUN apk add --no-cache dumb-init
+RUN apk add --no-cache dumb-init docker
 
 COPY --chown=node:node .gitignore .gitignore
 COPY --from=pruner --chown=node:node /app/out/json/ .