Fix import of CacheArgs in puffin-cli (#447)

```
error[E0432]: unresolved imports `puffin_cache::CacheArgs`, `puffin_cache::CacheDir`
  --> crates/puffin-cli/src/main.rs:11:20
   |
11 | use puffin_cache::{CacheArgs, CacheDir};
   |                    ^^^^^^^^^  ^^^^^^^^ no `CacheDir` in the root
   |                    |
   |                    no `CacheArgs` in the root
   |
note: found an item that was configured out
  --> /Users/mz/eng/src/astral-sh/puffin/crates/puffin-cache/src/lib.rs:7:15
   |
7  | pub use cli::{CacheArgs, CacheDir};
   |               ^^^^^^^^^
   = note: the item is gated behind the `clap` feature
note: found an item that was configured out
  --> /Users/mz/eng/src/astral-sh/puffin/crates/puffin-cache/src/lib.rs:7:26
   |
7  | pub use cli::{CacheArgs, CacheDir};
   |                          ^^^^^^^^
   = note: the item is gated behind the `clap` feature

For more information about this error, try `rustc --explain E0432`.
error: could not compile `puffin-cli` (bin "puffin") due to previous error
```

crates/puffin-cli/Cargo.toml

@@ -22,7 +22,7 @@ pep440_rs = { path = "../pep440-rs" }
 pep508_rs = { path = "../pep508-rs" }
 platform-host = { path = "../platform-host" }
 platform-tags = { path = "../platform-tags" }
-puffin-cache = { path = "../puffin-cache" }
+puffin-cache = { path = "../puffin-cache", features = ["clap"] }
 puffin-client = { path = "../puffin-client" }
 puffin-dispatch = { path = "../puffin-dispatch" }
 puffin-distribution = { path = "../puffin-distribution" }