Update subxt requirement from 0.29.0 to 0.37.0

Updates the requirements on [subxt](https://github.com/paritytech/subxt) to permit the latest version.
- [Release notes](https://github.com/paritytech/subxt/releases)
- [Changelog](https://github.com/paritytech/subxt/blob/master/CHANGELOG.md)
- [Commits](paritytech/subxt@v0.29.0...v0.37.0)

---
updated-dependencies:
- dependency-name: subxt
  dependency-type: direct:production
...

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

Cargo.toml

@@ -26,7 +26,7 @@ url = "2.2.2"
 base64 = "0.22.0"
 rand = "0.8.4"
 # subxt dependencies
-subxt = "0.29.0"
+subxt = "0.37.0"
 async-std = { version = "1.11.0", features = ["attributes", "tokio1"] }
 env_logger = "0.11.3"
 futures = "0.3.13"