Don't check Bats files using shell-lint.

They're meant for Bash and /bin/sh doesn't support everything that Bash
does.

.pre-commit-config.yaml

@@ -35,6 +35,7 @@ repos:
     rev: v0.6.0
     hooks:
       - id: shell-lint
+        exclude: \.bats$
 
   - repo: https://github.com/shellcheck-py/shellcheck-py.git
     rev: v0.7.1.1