Prevent --channel from being used with a single file in `pijul reset`

Dependencies

• [2] CCLLB7OI Upgrading to Sanakirja 0.15 + version bump
• [*] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).
• [*] VQPAUKBQ channel switch as an alias to reset

Change contents

• edit in pijul/src/commands/reset.rs at line 76
  [5.934]

  [2.12282]
  + if !self.files.is_empty() {

  + bail!("Cannot use --channel with individual paths. Did you mean --dry-run?")

  + }