Fix(test): Make template path unique in DataflowJobServiceTest (#35776)

* Fix(test): Make template path unique in DataflowJobServiceTest

The `DirectPipelineTemplateTest` used a hardcoded GCS path for the `template_location`. This can cause test flakiness due to collisions between concurrent test runs or leftover artifacts from previous runs.

This change uses `time.time()` to generate a unique template path for each test execution, ensuring test isolation and improving reliability.

* format

Author: liferoad

sdks/python/apache_beam/runners/dataflow/dataflow_job_service_test.py

@@ -15,6 +15,7 @@
 # limitations under the License.
 #
 
+import time
 import unittest
 
 import apache_beam as beam
@@ -63,14 +64,16 @@ def test_template(self):
         None, beam_job_type=dataflow_job_service.DataflowBeamJob)
     port = job_servicer.start_grpc_server(0)
     try:
+      template_path = (
+          'gs://apache-beam-testing-temp/test/template-{}'.format(time.time()))
       options = PipelineOptions(
           runner='PortableRunner',
           job_endpoint=f'localhost:{port}',
           project='apache-beam-testing',
           region='us-central1',
           staging_location='gs://apache-beam-testing-stg/stg/',
           temp_location='gs://apache-beam-testing-temp/tmp',
-          template_location='gs://apache-beam-testing-temp/test/template',
+          template_location=template_path,
       )
       with beam.Pipeline(options=options) as p:
         _ = p | beam.Create([1, 2, 3]) | beam.Map(lambda x: x * x)