Bump rust_decimal from 1.7.0 to 1.8.1

Bumps [rust_decimal](https://github.com/paupino/rust-decimal) from 1.7.0 to 1.8.1.
- [Release notes](https://github.com/paupino/rust-decimal/releases)
- [Commits](https://github.com/paupino/rust-decimal/commits/1.8.1)

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

Cargo.toml

@@ -20,7 +20,7 @@ cfg-if = "0.1"
 csv = "1.1.3"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-rust_decimal = "1.7"
+rust_decimal = "1.8"
 rand = "0.7"
 
 [target.'cfg(not(windows))'.dependencies]