Update mendes requirement from 0.2.0 to 0.3.0

Updates the requirements on [mendes](https://github.com/djc/mendes) to permit the latest version.
- [Commits](https://github.com/djc/mendes/commits)

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

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

askama_mendes/Cargo.toml

@@ -15,7 +15,7 @@ rust-version = "1.58"
 
 [dependencies]
 askama = { version = "0.12", path = "../askama", default-features = false, features = ["with-mendes", "mime", "mime_guess"] }
-mendes = "0.2.0"
+mendes = "0.3.0"
 
 [dev-dependencies]
 async-trait = "0.1.51"