Replace shellcheck pre-commit hook.

This one doesn't require having shellcheck installed (it's bundled in
the Python package).

.pre-commit-config.yaml

@@ -14,6 +14,10 @@ repos:
     rev: v0.6.0
     hooks:
       - id: shell-lint
+
+  - repo: https://github.com/shellcheck-py/shellcheck-py.git
+    rev: v0.7.1.1
+    hooks:
       - id: shellcheck
 
   - repo: https://git.shore.co.il/nimrod/git-pre-commit.git