Backport fix staking benchmark (#6463) to stable 2412

[gui1117]

Found by @ggwpez

Fix staking benchmark, error was introduced when migrating to v2: #6025

[github-actions]

This pull request is amending an existing release. Please proceed with extreme caution,
as to not impact downstream teams that rely on the stability of it. Some things to consider:

• Backports are only for 'patch' or 'minor' changes. No 'major' or other breaking change.
• Should be a legit fix for some bug, not adding tons of new features.
• Must either be already audited or not need an audit.

Emergency Bypass

If you really need to bypass this check: add validate: false to each crate
in the Prdoc where a breaking change is introduced. This will release a new major
version of that crate and all its reverse dependencies and basically break the release.

[gui1117]

I forced push because I needed to sign the commits

[gui1117]

merging is blocked: The base branch does not allow updates. But can we merge it still? the benchmark doesn't make any sense without this PR.