Get rid of pkg_resources

... because it was removed in Python 3.12 [1].

[1] https://docs.python.org/3/whatsnew/3.12.html#ensurepip

Change-Id: I2d27da0db92c1eaae9f45a0905e3eb905a939571

ironic_python_agent/agent.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import collections
+import importlib.metadata
 import ipaddress
 import random
 import socket
@@ -26,7 +27,6 @@ from ironic_lib import mdns
 from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_log import log
-import pkg_resources
 
 from ironic_python_agent.api import app
 from ironic_python_agent import config
@@ -233,8 +233,7 @@ class IronicPythonAgent(base.ExecuteCommandMixin):
         self.listen_address = listen_address
         self.advertise_address = advertise_address
         self.advertise_protocol = advertise_protocol
-        self.version = pkg_resources.get_distribution('ironic-python-agent')\
-            .version
+        self.version = importlib.metadata.version('ironic-python-agent')
         self.api = app.Application(self, cfg.CONF)
         self.heartbeat_timeout = None
         self.started_at = None

ironic_python_agent/tests/unit/test_agent.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import importlib.metadata
 import json
 import socket
 import time
@@ -20,7 +21,6 @@ from unittest import mock
 from ironic_lib import exception as lib_exc
 from oslo_concurrency import processutils
 from oslo_config import cfg
-import pkg_resources
 from stevedore import extension
 
 from ironic_python_agent import agent
@@ -230,8 +230,8 @@ class TestBaseAgent(ironic_agent_base.IronicAgentTest):
         status = self.agent.get_status()
         self.assertIsInstance(status, agent.IronicPythonAgentStatus)
         self.assertEqual(started_at, status.started_at)
-        self.assertEqual(pkg_resources.get_distribution('ironic-python-agent')
-                         .version, status.version)
+        self.assertEqual(importlib.metadata.version('ironic-python-agent'),
+                         status.version)
 
     @mock.patch(
         'ironic_python_agent.hardware_managers.cna._detect_cna_card',