feat: drop use of sys.version_info and TYPE_CHECKING

Removing the check for Python < 3.7 using `sys.version_info` and as a
backup checking `typing.TYPE_CHECKING`; this saves us a little space
and also cleans up the code. Proposing this as an enhancement beyond
what's in the `codegen2` branch / PR #4978.

packages/python/plotly/codegen/__init__.py

@@ -267,36 +267,24 @@ def perform_codegen(reformat=True):
         root_datatype_imports.append(f"._deprecations.{dep_clas}")
 
     optional_figure_widget_import = f"""
-if sys.version_info < (3, 7) or TYPE_CHECKING:
-    try:
-        import ipywidgets as _ipywidgets
-        from packaging.version import Version as _Version
-        if _Version(_ipywidgets.__version__) >= _Version("7.0.0"):
-            from ..graph_objs._figurewidget import FigureWidget
-        else:
-            raise ImportError()
-    except Exception:
-        from ..missing_anywidget import FigureWidget
-else:
-    __all__.append("FigureWidget")
-    orig_getattr = __getattr__
-    def __getattr__(import_name):
-        if import_name == "FigureWidget":
-            try:
-                import ipywidgets
-                from packaging.version import Version
-
-                if Version(ipywidgets.__version__) >= Version("7.0.0"):
-                    from ..graph_objs._figurewidget import FigureWidget
-
-                    return FigureWidget
-                else:
-                    raise ImportError()
-            except Exception:
-                from ..missing_anywidget import FigureWidget
+__all__.append("FigureWidget")
+orig_getattr = __getattr__
+def __getattr__(import_name):
+    if import_name == "FigureWidget":
+        try:
+            import ipywidgets
+            from packaging.version import Version
+
+            if Version(ipywidgets.__version__) >= Version("7.0.0"):
+                from ..graph_objs._figurewidget import FigureWidget
                 return FigureWidget
+            else:
+                raise ImportError()
+        except Exception:
+            from ..missing_anywidget import FigureWidget
+            return FigureWidget
 
-        return orig_getattr(import_name)
+    return orig_getattr(import_name)
 """
     # ### __all__ ###
     for path_parts, class_names in alls.items():

packages/python/plotly/codegen/utils.py

@@ -75,16 +75,12 @@ def build_from_imports_py(rel_modules=(), rel_classes=(), init_extra=""):
 
     result = f"""\
 import sys
-from typing import TYPE_CHECKING
-if sys.version_info < (3, 7) or TYPE_CHECKING:
-    {imports_str}
-else:
-    from _plotly_utils.importers import relative_import
-    __all__, __getattr__, __dir__ = relative_import(
-        __name__,
-        {repr(rel_modules)},
-        {repr(rel_classes)}
-    )
+from _plotly_utils.importers import relative_import
+__all__, __getattr__, __dir__ = relative_import(
+    __name__,
+    {repr(rel_modules)},
+    {repr(rel_classes)}
+)
 
 {init_extra}
 """