Update kernel env to reflect changes in session (#1354)

Author: blink1073

jupyter_server/services/sessions/sessionmanager.py

@@ -461,6 +461,13 @@ async def update_session(self, session_id, **kwargs):
         query = "UPDATE session SET %s WHERE session_id=?" % (", ".join(sets))  # noqa
         self.cursor.execute(query, [*list(kwargs.values()), session_id])
 
+        if hasattr(self.kernel_manager, "update_env"):
+            self.cursor.execute(
+                "SELECT path, name, kernel_id FROM session WHERE session_id=?", [session_id]
+            )
+            path, name, kernel_id = self.cursor.fetchone()
+            self.kernel_manager.update_env(kernel_id=kernel_id, env=self.get_kernel_env(path, name))
+
     async def kernel_culled(self, kernel_id: str) -> bool:
         """Checks if the kernel is still considered alive and returns true if its not found."""
         return kernel_id not in self.kernel_manager