ci: deploy staging-* only on demand

LW-10177

Author: michalrus

.github/workflows/std-release.yaml

@@ -9,7 +9,8 @@ jobs:
     if: startsWith(github.event.release.name, '@cardano-sdk/cardano-services@')
     uses: ./.github/workflows/std.yml
     with:
-      deploy-staging-preprod: true
+      # staging-* is deployed, with the versions and services identical to dev-*, at the start of the Lace release process:
+      deploy-staging-preprod: false
       deploy-dev-preprod: true
       deploy-dev-mainnet: true
     # Secrets have to be passed explicitly even if callee is in the same repo: