chore(deps): bump mockall from 0.14.0 to 0.15.0 in /bots/echidnabot

Bumps [mockall](https://github.com/asomers/mockall) from 0.14.0 to 0.15.0.
- [Changelog](https://github.com/asomers/mockall/blob/master/CHANGELOG.md)
- [Commits](asomers/mockall@v0.14.0...v0.15.0)

---
updated-dependencies:
- dependency-name: mockall
  dependency-version: 0.15.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

bots/echidnabot/Cargo.lock

@@ -79,7 +79,7 @@ urlencoding = "2.1.3"
 criterion = { version = "0.8.2", features = ["html_reports"] }
 tokio-test = "0.4.5"
 axum-test = "21.0.0"
-mockall = "0.14.0"
+mockall = "0.15.0"
 tempfile = "3.27.0"
 wiremock = "0.6.5"
 bytes = "1.11.1"