chore(deps): update soroban-sdk requirement in /smartcontract

Updates the requirements on [soroban-sdk](https://github.com/stellar/rs-soroban-sdk) to permit the latest version.
- [Release notes](https://github.com/stellar/rs-soroban-sdk/releases)
- [Commits](stellar/rs-soroban-sdk@v21.0.1-preview.1...v27.0.0)

---
updated-dependencies:
- dependency-name: soroban-sdk
  dependency-version: 27.0.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

smartcontract/Cargo.toml

@@ -7,10 +7,10 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = { version = "21.0.0" }
+soroban-sdk = { version = "27.0.0" }
 
 [dev-dependencies]
-soroban-sdk = { version = "21.0.0", features = ["testutils"] }
+soroban-sdk = { version = "27.0.0", features = ["testutils"] }
 proptest = "1"
 
 [profile.release]