Fix side-effect of default options in Beam Operators (#37916)

Some of the operators in Apache Beam had side effect that they
modified detault options passed to it in constructor, and in case
of xdist tests it had side effect that they could impact other
test results (this happened recently in main). The default options
are already set by the Dataflow mixin in execute method in all
Beam operators, but in Python and Go operator the defaults
are also set in the constructor.

Setting the defaults in mixin uses deepcopy to avoid such side effects.

This might  be intended, so this PR rather than removing default
settings in the constructor, also adds deepcopy in them and fixes
resulting tests - removing the defaults in tests that do not
have the defaults set in the constructor.

airflow/providers/apache/beam/operators/beam.py

@@ -333,6 +333,7 @@ def __init__(
         self.py_interpreter = py_interpreter
         self.py_requirements = py_requirements
         self.py_system_site_packages = py_system_site_packages
+        self.pipeline_options = copy.deepcopy(self.pipeline_options)
         self.pipeline_options.setdefault("labels", {}).update(
             {"airflow-version": "v" + version.replace(".", "-").replace("+", "-")}
         )
@@ -740,7 +741,7 @@ def __init__(
         self.go_file = go_file
         self.launcher_binary = launcher_binary
         self.worker_binary = worker_binary or launcher_binary
-
+        self.pipeline_options = copy.deepcopy(self.pipeline_options)
         self.pipeline_options.setdefault("labels", {}).update(
             {"airflow-version": "v" + version.replace(".", "-").replace("+", "-")}
         )

tests/providers/apache/beam/operators/test_beam.py

@@ -60,6 +60,7 @@
     "output": "gs://test/output",
     "labels": {"foo": "bar", "airflow-version": TEST_VERSION},
 }
+
 TEST_IMPERSONATION_ACCOUNT = "test@impersonation.com"
 BEAM_OPERATOR_PATH = "airflow.providers.apache.beam.operators.beam.{}"
 
@@ -286,7 +287,7 @@ def test_exec_dataflow_runner(self, gcs_hook, dataflow_hook_mock, beam_hook_mock
             "jobName": job_name,
             "stagingLocation": "gs://test/staging",
             "region": "us-central1",
-            "labels": {"foo": "bar", "airflow-version": TEST_VERSION},
+            "labels": {"foo": "bar"},
             "output": "gs://test/output",
             "impersonateServiceAccount": TEST_IMPERSONATION_ACCOUNT,
         }
@@ -926,7 +927,7 @@ def test_exec_dataflow_runner(self, gcs_hook, dataflow_hook_mock, beam_hook_mock
             "job_name": job_name,
             "staging_location": "gs://test/staging",
             "output": "gs://test/output",
-            "labels": {"foo": "bar", "airflow-version": TEST_VERSION},
+            "labels": {"foo": "bar"},
             "region": "us-central1",
             "impersonate_service_account": TEST_IMPERSONATION_ACCOUNT,
         }