test(exporter-otlp-proto-grpc): relax timing delta and deadline error string assertion in mixin tests (#5666)

Assisted-by: Gemini

Author: dashpole

exporter/opentelemetry-exporter-otlp-proto-grpc/tests/test_otlp_exporter_mixin.py

@@ -445,7 +445,7 @@ def test_retry_info_is_respected(self):
         after = time.time()
         self.assertEqual(mock_trace_service.num_requests, 6)
         # 1 second plus wiggle room so the test passes consistently.
-        self.assertAlmostEqual(after - before, 1, 1)
+        self.assertAlmostEqual(after - before, 1, delta=0.5)
 
         metrics_data = self.metric_reader.get_metrics_data()
         scope_metrics = metrics_data.resource_metrics[0].scope_metrics[0]
@@ -526,12 +526,12 @@ def test_timeout_set_correctly(self):
                     SpanExportResult.FAILURE,
                 )
             after = time.time()
-            self.assertEqual(
-                "Failed to export traces to localhost:4317, error code: StatusCode.DEADLINE_EXCEEDED, error details: Deadline Exceeded",
+            self.assertIn(
+                "error code: StatusCode.DEADLINE_EXCEEDED",
                 warning.records[-1].message,
             )
             self.assertEqual(mock_trace_service.num_requests, 2)
-            self.assertAlmostEqual(after - before, 1.4, 1)
+            self.assertAlmostEqual(after - before, 1.4, delta=0.5)
 
     def test_channel_options_set_correctly(self):
         """Test that gRPC channel options are set correctly for keepalive and reconnection"""