Core: Fix remaining six.py relative imports and replace imp module

Replace all 17 remaining from .six relative imports with inline
constants (string_types = str, PY2 = False). Replace imp.load_source
with importlib.util in custom_step_widget.py and rbf_manager_ui.py
(imp module removed in Python 3.12/Maya 2027).

Author: miquelcampos

release/scripts/mgear/core/anim_utils.py

@@ -3,7 +3,7 @@
 import traceback
 from functools import partial
 
-from .six import PY2
+PY2 = False
 
 # Maya imports
 from maya import cmds

release/scripts/mgear/core/applyop.py

@@ -17,7 +17,7 @@
 from mgear.pymaya import datatypes
 
 import maya.api.OpenMaya as om
-from .six import string_types
+string_types = str
 
 from mgear.core import attribute
 from mgear.core import surface

release/scripts/mgear/core/attribute.py

@@ -11,7 +11,7 @@
 import mgear
 import mgear.pymaya as pm
 import mgear.pymaya.datatypes as datatypes
-from .six import string_types
+string_types = str
 
 #############################################
 # NODE

release/scripts/mgear/core/curve.py

@@ -19,7 +19,7 @@
 from mgear.core import utils
 from mgear.core import transform
 
-from .six import string_types
+string_types = str
 
 #############################################
 # CURVE

release/scripts/mgear/core/dagmenu.py

@@ -39,7 +39,7 @@
 from mgear.shifter import io
 from mgear.shifter import guide_template
 
-from .six import string_types
+string_types = str
 
 from mgear.vendor.Qt import QtWidgets
 from mgear.compatible import compatible_comp_dagmenu

release/scripts/mgear/core/node.py

@@ -6,7 +6,8 @@
 import mgear.pymaya.datatypes as datatypes
 from mgear.core import attribute
 
-from .six import PY2, string_types
+PY2 = False
+string_types = str
 
 # Type tuple for faster isinstance checks (used frequently in node creation)
 _CONNECTABLE_TYPES = None

release/scripts/mgear/core/pyqt.py

@@ -16,7 +16,7 @@
 from mgear.vendor.Qt import QtGui
 from mgear.vendor.Qt import QtSvg
 from mgear.vendor.Qt import QtCore
-from .six import PY2
+PY2 = False
 
 # Try importing PySide6, fall back to PySide2 if not available
 try:

release/scripts/mgear/core/skin.py

@@ -18,7 +18,7 @@
 from maya import cmds
 import maya.OpenMaya as OpenMaya
 import maya.OpenMayaAnim as OpenMayaAnim
-from .six import string_types
+string_types = str
 from mgear.vendor.Qt import QtWidgets
 from mgear.vendor.Qt import QtCore
 from mgear.vendor.Qt import QtGui

release/scripts/mgear/core/utils.py

@@ -12,7 +12,8 @@
 import mgear.pymaya as pm
 from maya import mel
 import maya.api.OpenMaya as OpenMaya
-from .six import string_types, PY2
+string_types = str
+PY2 = False
 
 import mgear
 

release/scripts/mgear/core/wmap.py

@@ -5,7 +5,7 @@
 from maya import cmds
 import mgear.pymaya as pm
 import maya.OpenMaya as OpenMaya
-from .six import string_types
+string_types = str
 
 FILE_EXT = ".wmap"