rpassword 7.5.0 fails to compile on macOS (uses Linux-only __errno_location)

[sdairs]

Issue

After #140 bumped rpassword from 7.4.0 to 7.5.0, local `cargo build` fails on macOS:

```
error[E0425]: cannot find function `__errno_location` in crate `libc`
--> ~/.cargo/registry/src/.../rpassword-7.5.0/src/unix.rs:26:16
|
26 | *libc::__errno_location() = 0;
| ^^^^^^^^^^^^^^^^ not found in `libc`
```

`__errno_location` is glibc-only — macOS/Darwin libc exposes `__error` instead. Known upstream regression in rpassword 7.5.0.

Impact

• Local `cargo build` is broken on every macOS workstation.
• CI `Install Test (macos-14)` and `Install Test (macos-15)` jobs are failing with the same error (visible on PR #144 checks).
• Linux CI keeps working because `__errno_location` exists in glibc.

Suggested fix

Pin `rpassword` to `"7.4"` in `crates/clickhousectl/Cargo.toml` until 7.5.x is fixed upstream:

```toml
rpassword = "7.4"
```

Repro

```
git checkout main
cargo build -p clickhousectl
```

Also reproduces on any branch off current main.

[sdairs]

Fixing in PR #144 by bumping rpassword to 7.5.2 directly.