STYLE: Replace default capture ParallelizeImageRegionRestrictDirection

Instead of capturing everything by reference (by default capture `&`), captured
the parameter `restrictedDirection` by value. `restrictedDirection` is
lightweight (it's an `unsigned int`), and it is not modified by the lambda,
so there is no reason to capture it by reference.

Modules/Core/Common/include/itkMultiThreaderBase.h

@@ -390,7 +390,7 @@ ITK_GCC_PRAGMA_DIAG_POP()
         SplitDimension,
         splitIndex.m_InternalArray,
         splitSize.m_InternalArray,
-        [&](const IndexValueType index[], const SizeValueType size[]) {
+        [restrictedDirection, &requestedRegion, &funcP](const IndexValueType index[], const SizeValueType size[]) {
           ImageRegion<VDimension> restrictedRequestedRegion;
           restrictedRequestedRegion.SetIndex(restrictedDirection, requestedRegion.GetIndex(restrictedDirection));
           restrictedRequestedRegion.SetSize(restrictedDirection, requestedRegion.GetSize(restrictedDirection));