chore(deps-dev): update mypy requirement (#414)

Author: dependabot[bot]

pyproject.toml

@@ -63,7 +63,7 @@ actions = [
 ]
 dev = [
     "flit >=3.2.0,<4.0.0",
-    "mypy >=0.921,<1.5",
+    "mypy >=0.921,<1.6",
     "types-pyyaml >=6.0.4,<7.0.0",
     "types-requests >=2.25.6,<3.0.0",
     "pip-audit >=2.5.6,<3.0.0",