chore(deps): bump axum-test from 18.7.0 to 20.0.0 in /bots/echidnabot

Bumps [axum-test](https://github.com/JosephLenton/axum-test) from 18.7.0 to 20.0.0.
- [Release notes](https://github.com/JosephLenton/axum-test/releases)
- [Commits](https://github.com/JosephLenton/axum-test/commits)

---
updated-dependencies:
- dependency-name: axum-test
  dependency-version: 20.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

bots/echidnabot/Cargo.lock

@@ -78,7 +78,7 @@ urlencoding = "2"
 [dev-dependencies]
 criterion = { version = "0.5", features = ["html_reports"] }
 tokio-test = "0.4"
-axum-test = "18"
+axum-test = "20"
 mockall = "0.14"
 tempfile = "3"
 wiremock = "0.6"