fix: ruff import order and line length in session.py

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

Author: verdie-g

src/mcp/server/session.py

@@ -28,6 +28,7 @@ async def handle_list_prompts(ctx: RequestContext, params) -> ListPromptsResult:
 be instantiated directly by users of the MCP framework.
 """
 
+import time
 from enum import Enum
 from typing import Any, TypeVar, overload
 
@@ -40,8 +41,6 @@ async def handle_list_prompts(ctx: RequestContext, params) -> ListPromptsResult:
 from mcp.server.experimental.session_features import ExperimentalServerSessionFeatures
 from mcp.server.models import InitializationOptions
 from mcp.server.validation import validate_sampling_tools, validate_tool_use_result_messages
-import time
-
 from mcp.shared._otel import record_server_session_duration
 from mcp.shared._stream_protocols import ReadStream, WriteStream
 from mcp.shared.exceptions import StatelessModeNotSupported
@@ -105,7 +104,9 @@ async def __aenter__(self) -> "ServerSession":
         self._session_start_time = time.monotonic()
         return await super().__aenter__()
 
-    async def __aexit__(self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: Any) -> bool | None:
+    async def __aexit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: Any
+    ) -> bool | None:
         if self._session_start_time is not None:
             duration = time.monotonic() - self._session_start_time
             mcp_protocol_version: str | None = (