Update scraper requirement from 0.20 to 0.21

Updates the requirements on [scraper](https://github.com/causal-agent/scraper) to permit the latest version.
- [Release notes](https://github.com/causal-agent/scraper/releases)
- [Commits](rust-scraper/scraper@v0.20.0...v0.21.0)

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

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

Cargo.toml

@@ -42,7 +42,7 @@ http-types = "2"
 hyper = { version = "1.0", default-features = false, features = ["client", "http1", "server"] }
 macro_rules_attribute = "0.2.0"
 native-tls = "0.2"
-scraper = "0.20"
+scraper = "0.21"
 signal-hook = "0.3"
 smol-hyper = "0.1.0"
 smol-macros = "0.1.0"