drop async-service dep and copy relevant code into a local async_service

tool, updated for modern handling of ExceptionGroup

libp2p/tools/async_service/exceptions.py

@@ -0,0 +1,26 @@
+# Copied from https://github.com/ethereum/async-service
+
+
+class ServiceException(Exception):
+    """
+    Base class for Service exceptions
+    """
+
+
+class LifecycleError(ServiceException):
+    """
+    Raised when an action would violate the service lifecycle rules.
+    """
+
+
+class DaemonTaskExit(ServiceException):
+    """
+    Raised when an action would violate the service lifecycle rules.
+    """
+
+
+class TooManyChildrenException(ServiceException):
+    """
+    Raised when a service adds too many children. It is a sign of task leakage
+    that needs to be prevented.
+    """