tox.ini: Make mypy allow unused "type: ignore" comments

tox.ini

@@ -27,9 +27,16 @@ deps =
     mypy        == 1.8.0
     pytest-mypy >= 0.10.3
 basepython = py38
+
+# Don't have mypy report unused ignores. Pyright is used
+# for day-to-day development, while mypy is used for code
+# quality checks. mypy will not always produce an error
+# where pyright does. Specifically, calling an abstract
+# class method produces a pyright type error, but it
+# does not trigger a mypy error when testing.
 commands =
     mypy --version
-    mypy --strict src/ tests/
+    mypy --no-warn-unused-ignores --strict src/ tests/
 
 [testenv:docs]
 # sphinx imports d2lfg to get the library version in docs/source/conf.py.