chore: enable clippy::redundant_clone (#3489)

Created this PR by:

- adding `redundant_clone` to `[workspace.lints.clippy]` in
`cargo-rs/Cargol.toml`
- running `cargo clippy --tests --fix`
- running `just fmt`

Though I had to clean up one instance of the following that resulted:

```rust
let codex = codex;
```

codex-rs/execpolicy/src/policy_parser.rs

@@ -104,7 +104,7 @@ impl PolicyBuilder {
         info!("adding program spec: {program_spec:?}");
         let name = program_spec.program.clone();
         let mut programs = self.programs.borrow_mut();
-        programs.insert(name.clone(), program_spec);
+        programs.insert(name, program_spec);
     }
 
     fn add_forbidden_substrings(&self, substrings: &[String]) {