Fix typo in pre-commit config (#517)

Author: lfrancke

template/.pre-commit-config.yaml.j2

@@ -68,7 +68,7 @@ repos:
  language: system
  entry: make regenerate-nix
  stages: [pre-commit, pre-merge-commit]
- pass_filename: false
+ pass_filenames: false
  files: Cargo\.lock
 
  - id: cargo-test