fix: remove unused variable warning on Windows builds

Move cfg(unix) attribute to the if statement level instead of inside
the block. This prevents the metadata binding from being created on
Windows where it's unused.

Closes #382

Author: joshrotenberg

crates/redisctl/src/commands/enterprise/support_package.rs

@@ -396,16 +396,13 @@ fn perform_preflight_checks(output_path: &Path) -> AnyhowResult<()> {
     }
 
     // Check available disk space (warn if less than 1GB)
+    // Only perform check on Unix systems where we can read block count
+    #[cfg(unix)]
     if let Ok(metadata) = fs::metadata(parent_dir) {
-        // This is platform-specific and would need proper implementation
-        // For now, just a placeholder check
-        #[cfg(unix)]
-        {
-            use std::os::unix::fs::MetadataExt;
-            // Basic check - would need proper disk space checking
-            if metadata.blocks() < 1000000 {
-                eprintln!("Warning: Low disk space detected");
-            }
+        use std::os::unix::fs::MetadataExt;
+        // Basic check - would need proper disk space checking
+        if metadata.blocks() < 1000000 {
+            eprintln!("Warning: Low disk space detected");
         }
     }