fix: use pragma lax no cover for version-dependent imports

strict-no-cover flags 'pragma: no cover' as incorrect when the lines
ARE covered on the running Python version. Use 'pragma: lax no cover'
instead, which is excluded from both coverage counting and strict
checking.

Author: g97iulio1609

src/mcp/shared/_exception_utils.py

@@ -20,7 +20,7 @@
 import anyio
 import anyio.abc
 
-if sys.version_info < (3, 11):  # pragma: no cover
+if sys.version_info < (3, 11):  # pragma: lax no cover
     from exceptiongroup import BaseExceptionGroup
 
 

src/mcp/shared/session.py

@@ -14,7 +14,7 @@
 
 from mcp.shared._exception_utils import collapse_exception_group
 
-if sys.version_info < (3, 11):  # pragma: no cover
+if sys.version_info < (3, 11):  # pragma: lax no cover
     from exceptiongroup import BaseExceptionGroup
 from mcp.shared.exceptions import MCPError
 from mcp.shared.message import MessageMetadata, ServerMessageMetadata, SessionMessage

tests/shared/test_exception_utils.py

@@ -10,7 +10,7 @@
 
 from mcp.shared._exception_utils import collapse_exception_group, open_task_group
 
-if sys.version_info < (3, 11):  # pragma: no cover
+if sys.version_info < (3, 11):  # pragma: lax no cover
     from exceptiongroup import BaseExceptionGroup