fixes after review

pyproject.toml

@@ -70,8 +70,7 @@ source = ["exceptiongroup"]
 relative_files = true
 
 [tool.coverage.report]
-exclude_lines = [
-    "pragma: no cover",
+exclude_also = [
     "if TYPE_CHECKING:",
     "@overload",
 ]
@@ -86,9 +85,8 @@ skip_missing_interpreters = true
 minversion = 4.0
 
 [testenv]
-deps = coverage
 extras = test
-commands = coverage run -p -m pytest {posargs}
+commands = python -m pytest {posargs}
 usedevelop = true
 
 [testenv:{py37-,py38-,py39-,py310-,py311-,py312-,}pyright]

src/exceptiongroup/_suppress.py

@@ -1,7 +1,7 @@
 import sys
 from contextlib import AbstractContextManager
 from types import TracebackType
-from typing import TYPE_CHECKING, Type
+from typing import TYPE_CHECKING, Optional, Type
 
 if sys.version_info < (3, 11):
     from ._exceptions import BaseExceptionGroup
@@ -23,7 +23,10 @@ def __enter__(self) -> None:
         pass
 
     def __exit__(
-        self, exctype: Type[BaseException], excinst: BaseException, exctb: TracebackType
+        self,
+        exctype: Optional[Type[BaseException]],
+        excinst: Optional[BaseException],
+        exctb: Optional[TracebackType],
     ) -> bool:
         # Unlike isinstance and issubclass, CPython exception handling
         # currently only looks at the concrete type hierarchy (ignoring