fix: conditionally import unused modules on Windows

Make std::fs, std::process::Command, and tracing macros (debug, info)
conditional with #[cfg(unix)] to avoid unused import warnings on Windows
where the OpenTofu installer returns early.

Co-authored-by: josecelano <58816+josecelano@users.noreply.github.com>

Author: Copilot

packages/dependency-installer/src/installer/opentofu.rs

@@ -3,11 +3,14 @@
 //! This module provides installation logic for the `OpenTofu` dependency.
 
 // Standard library
+#[cfg(unix)]
 use std::fs;
+#[cfg(unix)]
 use std::process::Command;
 
 // External crates
 use async_trait::async_trait;
+#[cfg(unix)]
 use tracing::{debug, info};
 
 // Internal crate