Enable clippy lints on a workspace level

This enables a lot more lints than before in some crates, so this fixed a lot of warnings as well.

crates/email/Cargo.toml

@@ -7,6 +7,9 @@ license.workspace = true
 homepage.workspace = true
 repository.workspace = true
 
+[lints]
+workspace = true
+
 [dependencies]
 async-trait = "0.1.74"
 tracing.workspace = true

crates/email/src/lib.rs

@@ -14,14 +14,7 @@
 
 //! Helps sending emails to users, with different email backends
 
-#![forbid(unsafe_code)]
-#![deny(
-    clippy::all,
-    clippy::str_to_string,
-    missing_docs,
-    rustdoc::broken_intra_doc_links
-)]
-#![warn(clippy::pedantic)]
+#![deny(missing_docs)]
 
 mod mailer;
 mod transport;