fix(test): Suggest -- for libtest arguments

We already do this so long as the argument doesn't look like a
`cargo test` argument (e.g. `--show-output`)
but `--ignored` looks like `--ignore-rust-version` do the the suggestion
algorithms prefix checks.

Before
```
error: unexpected argument '--ignored' found

  tip: a similar argument exists: '--ignore-rust-version'

Usage: cargo test --ignore-rust-version [TESTNAME] [-- [ARGS]...]

For more information, try '--help'.
```
After
```
error: unexpected argument '--ignored' found

  tip: a similar argument exists: '--ignore-rust-version'
  tip: to pass '--ignored' as a value, use '-- --ignored'

Usage: cargo test --ignore-rust-version [TESTNAME] [-- [ARGS]...]

For more information, try '--help'.
```

Fixes rust-lang#12494

Cargo.toml

@@ -35,7 +35,7 @@ cargo-test-support = { path = "crates/cargo-test-support" }
 cargo-util = { version = "0.2.6", path = "crates/cargo-util" }
 cargo-util-schemas = { version = "0.2.0", path = "crates/cargo-util-schemas" }
 cargo_metadata = "0.18.1"
-clap = "4.4.18"
+clap = "4.5.1"
 color-print = "0.3.5"
 core-foundation = { version = "0.9.4", features = ["mac_os_10_7_support"] }
 crates-io = { version = "0.40.0", path = "crates/crates-io" }