Function build_downgrade_command_for_executor 

pub fn build_downgrade_command_for_executor(
    names: &[String],
    _password: Option<&str>,
    dry_run: bool,
) -> String

What: Build downgrade command string without hold tail for PTY execution.

Inputs:

• names: Package names to downgrade.
• _password: Optional sudo password (unused - password is written to PTY stdin when sudo prompts).
• dry_run: Whether to run in dry-run mode.

Output:

• Command string ready for PTY execution (no hold tail).

Details:

• Uses the downgrade tool to downgrade packages.
• Checks if downgrade tool is available before executing.
• Password is written to PTY stdin when sudo prompts, so we don’t need to pipe it here.
• Removes hold tail since we’re not spawning a terminal.