Update pollster requirement from 0.3 to 0.4

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

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

Author: dependabot[bot]

Cargo.toml

@@ -86,7 +86,7 @@ opt-level = 1
 static_assertions = "1"
 
 [target.'cfg(not(target_family = "wasm"))'.dev-dependencies]
-pollster = { version = "0.3", features = ["macro"] }
+pollster = { version = "0.4", features = ["macro"] }
 ui_test = "0.25"
 
 [target.'cfg(target_family = "wasm")'.dev-dependencies]