chore: fix mypy issues

Author: lepture

.pre-commit-config.yaml

@@ -1,13 +1,19 @@
 ---
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: 'v0.11.6'
+    rev: 'v0.13.0'
     hooks:
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]
       - id: ruff-format
+
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: 'v1.18.1'
+    hooks:
+      - id: mypy
+
   - repo: https://github.com/codespell-project/codespell
-    rev: v2.4.1
+    rev: 'v2.4.1'
     hooks:
     - id: codespell
       additional_dependencies:

src/joserfc/registry.py

@@ -213,6 +213,6 @@ def check_crit_header(registry: HeaderRegistryDict, header: Header) -> None:
         raise UnsupportedHeaderError(f"Unsupported {unsupported_crit_headers} in header")
 
 
-def reject_unprotected_crit_header(unprotected: Header) -> None:
+def reject_unprotected_crit_header(unprotected: Header | None) -> None:
     if unprotected and "crit" in unprotected:
         raise UnsupportedHeaderError("'crit' header MUST be protected header")