Remove deprecated CombineColumns step

src/distilabel/steps/columns/group.py

@@ -12,8 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import warnings
-from typing import TYPE_CHECKING, Any, List, Optional
+from typing import TYPE_CHECKING, List, Optional
 
 from typing_extensions import override
 
@@ -125,15 +124,3 @@ def process(self, *inputs: StepInput) -> "StepOutput":
             group_columns=self.inputs,
             output_group_columns=self.outputs,
         )
-
-
-class CombineColumns(GroupColumns):
-    """`CombineColumns` is deprecated and will be removed in version 1.5.0, use `GroupColumns` instead."""
-
-    def __init__(self, **data: Any) -> None:
-        warnings.warn(
-            "`CombineColumns` is deprecated and will be removed in version 1.5.0, use `GroupColumns` instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return super().__init__(**data)

tests/unit/steps/columns/test_group.py

@@ -13,11 +13,9 @@
 # limitations under the License.
 
 
-import pytest
-
 from distilabel.constants import DISTILABEL_METADATA_KEY
 from distilabel.pipeline.local import Pipeline
-from distilabel.steps.columns.group import CombineColumns, GroupColumns
+from distilabel.steps.columns.group import GroupColumns
 
 
 class TestGroupColumns:
@@ -58,16 +56,3 @@ def test_process(self) -> None:
                 DISTILABEL_METADATA_KEY: {"model": ["model-1", "model-2"]},
             }
         ]
-
-
-def test_CombineColumns_deprecation_warning():
-    with pytest.deprecated_call():
-        CombineColumns(
-            name="combine_columns",
-            columns=["generation", "model_name"],
-        )
-    from packaging.version import Version
-
-    import distilabel
-
-    assert Version(distilabel.__version__) <= Version("1.5.0")