Update password generator to new Rand API

Replace `thread_rng` with `rng` and use `random_range` for character
selection. Rename the `component` argument to `_component` in
`PackageManager::download_binary` to suppress an unused‑parameter
warning.

src/bootstrap/mod.rs

@@ -424,10 +424,10 @@ impl BootstrapManager {
     fn generate_password(&self) -> String {
         use rand::Rng;
         const CHARSET: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
-        let mut rng = rand::thread_rng();
+        let mut rng = rand::rng();
         (0..16)
             .map(|_| {
-                let idx = rng.gen_range(0..CHARSET.len());
+                let idx = rng.random_range(0..CHARSET.len());
                 CHARSET[idx] as char
             })
             .collect()

src/package_manager/mod.rs

@@ -1164,7 +1164,7 @@ impl PackageManager {
         &self,
         container: &str,
         url: &str,
-        component: &str,
+        _component: &str,
         binary_name: Option<&str>,
     ) -> Result<()> {
         let download_cmd = format!("wget -O /tmp/download.tmp {}", url);