Update reqwest-middleware requirement from 0.3.0 to 0.4.0

Updates the requirements on [reqwest-middleware](https://github.com/TrueLayer/reqwest-middleware) to permit the latest version.
- [Release notes](https://github.com/TrueLayer/reqwest-middleware/releases)
- [Commits](TrueLayer/reqwest-middleware@reqwest-middleware-v0.3.0...reqwest-middleware-v0.4.0)

---
updated-dependencies:
- dependency-name: reqwest-middleware
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Cargo.toml

@@ -47,7 +47,7 @@ tracing = {version = "0.1", optional = true}
 uuid = {version = ">=0.7.0, <2.0.0", features = ["serde", "v4"]}
 chacha20poly1305 = { version = "0.10.1", features = ["std"], optional = true }
 
-reqwest-middleware = { version = "0.3.0", features = ["json", "multipart"] }
+reqwest-middleware = { version = "0.4.0", features = ["json", "multipart"] }
 http = "1.0.0"
 
 opentelemetry_0_20_pkg = { package = "opentelemetry", version = "0.20", optional = true }