Merge pull request InsightSoftwareConsortium#5911 from N-Dekker/Remove-NthElementPixelAccessor-operator=-VariableLengthVector

COMP: Remove `NthElementPixelAccessor::operator=` for VariableLengthVector

Author: hjmjohnson

Modules/Core/ImageAdaptors/include/itkNthElementPixelAccessor.h

@@ -199,15 +199,6 @@ class NthElementPixelAccessor<TOutputPixelType, itk::VariableLengthVector<TPixel
 
   ITK_UNEQUAL_OPERATOR_MEMBER_FUNCTION(Self);
 
-  /** Assignment operator */
-  NthElementPixelAccessor &
-  operator=(const NthElementPixelAccessor & accessor)
-  {
-    m_ElementNumber = accessor.m_ElementNumber;
-    this->SetVectorLength(accessor.GetVectorLength());
-    return *this;
-  }
-
 protected:
   using Superclass = DefaultVectorPixelAccessor<TPixelType>;