Avoid change attributes into the constructor in Apache Beam operators (…

…apache#37934)

* Avoid change attributes into the init method in Apache Beam operators

* Remove commented out code

* Remove useless constants

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

@@ -180,15 +180,19 @@ def __init__(
         self.runner = runner
         self.default_pipeline_options = default_pipeline_options or {}
         self.pipeline_options = pipeline_options or {}
+        # ``dataflow_config`` type will resolve into the execute method
+        self.dataflow_config = dataflow_config or {}  # type: ignore[assignment]
         self.gcp_conn_id = gcp_conn_id
-        if isinstance(dataflow_config, dict):
-            self.dataflow_config = DataflowConfiguration(**dataflow_config)
-        else:
-            self.dataflow_config = dataflow_config or DataflowConfiguration()
         self.beam_hook: BeamHook
         self.dataflow_hook: DataflowHook | None = None
         self.dataflow_job_id: str | None = None
 
+    def _cast_dataflow_config(self):
+        if isinstance(self.dataflow_config, dict):
+            self.dataflow_config = DataflowConfiguration(**self.dataflow_config)
+        else:
+            self.dataflow_config = self.dataflow_config or DataflowConfiguration()
+
         if self.dataflow_config and self.runner.lower() != BeamRunnerType.DataflowRunner.lower():
             self.log.warning(
                 "dataflow_config is defined but runner is different than DataflowRunner (%s)", self.runner
@@ -333,14 +337,14 @@ 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("+", "-")}
-        )
         self.deferrable = deferrable
 
     def execute(self, context: Context):
         """Execute the Apache Beam Python Pipeline."""
+        self._cast_dataflow_config()
+        self.pipeline_options.setdefault("labels", {}).update(
+            {"airflow-version": "v" + version.replace(".", "-").replace("+", "-")}
+        )
         (
             self.is_dataflow,
             self.dataflow_job_name,
@@ -527,6 +531,7 @@ def __init__(
 
     def execute(self, context: Context):
         """Execute the Apache Beam Python Pipeline."""
+        self._cast_dataflow_config()
         (
             self.is_dataflow,
             self.dataflow_job_name,
@@ -727,27 +732,26 @@ def __init__(
             dataflow_config=dataflow_config,
             **kwargs,
         )
+        self.go_file = go_file
+        self.launcher_binary = launcher_binary
+        self.worker_binary = worker_binary or launcher_binary
 
+    def execute(self, context: Context):
+        """Execute the Apache Beam Pipeline."""
+        if not exactly_one(self.go_file, self.launcher_binary):
+            raise ValueError("Exactly one of `go_file` and `launcher_binary` must be set")
+
+        self._cast_dataflow_config()
         if self.dataflow_config.impersonation_chain:
-            self.log.info(
+            self.log.warning(
                 "Impersonation chain parameter is not supported for Apache Beam GO SDK and will be skipped "
                 "in the execution"
             )
         self.dataflow_support_impersonation = False
-
-        if not exactly_one(go_file, launcher_binary):
-            raise ValueError("Exactly one of `go_file` and `launcher_binary` must be set")
-
-        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("+", "-")}
         )
 
-    def execute(self, context: Context):
-        """Execute the Apache Beam Pipeline."""
         (
             is_dataflow,
             dataflow_job_name,