chore(deps): bump sp-storage from 20.0.0 to 21.0.0 (#812)

Bumps [sp-storage](https://github.com/paritytech/polkadot-sdk) from 20.0.0 to 21.0.0.
- [Release notes](https://github.com/paritytech/polkadot-sdk/releases)
- [Changelog](https://github.com/paritytech/polkadot-sdk/blob/master/docs/RELEASE.md)
- [Commits](https://github.com/paritytech/polkadot-sdk/commits)

---
updated-dependencies:
- dependency-name: sp-storage
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Cargo.toml

@@ -42,5 +42,5 @@ once_cell = "1.19"
 [dev-dependencies]
 anyhow = "1"
 assert_cmd = "2.0"
-sp-storage = "20.0.0"
+sp-storage = "21.0.0"
 regex = "1"