[db] Migrations image: explicitly add bash (#20732)

Author: geropl

Diff for: components/gitpod-db/leeway.Dockerfile

@@ -18,6 +18,12 @@ RUN wget https://storage.googleapis.com/cloudsql-proxy/v1.37.6/cloud_sql_proxy.l
  && chmod +x /bin/cloud_sql_proxy
 
 FROM node:18.20.7-alpine
+
+# Install bash
+RUN apk update && \
+    apk add bash && \
+    rm -rf /var/cache/apk/*
+
 ENV NODE_OPTIONS=--unhandled-rejections=warn
 COPY migrate.sh /app/migrate.sh
 COPY migrate_gcp.sh /app/migrate_gcp.sh