pyproject.toml: Add tool.mypy section

And remove equivalent switches from mypy.sh script to avoid
duplication.

.ci/mypy.sh

@@ -10,4 +10,4 @@ fi
 
 set -x
 
-mypy mrhlpr.py mrtest.py --check-untyped-defs --disallow-untyped-calls
\ No newline at end of file
+mypy mrhlpr.py mrtest.py

pyproject.toml

@@ -43,3 +43,7 @@ include = ["mrhlpr*", "mrtest*"]
 
 [tool.ruff]
 line-length=100
+
+[tool.mypy]
+check_untyped_defs = true
+disallow_untyped_calls = true