Invalid vector comparisons in HLSL shader code

In some cases OCIO generates invalid HLSL code like this:
`if ( gamma != float3(1., 1., 1.) )`

This fails compilation with the following error:
`error X3019: if statement conditional expressions must evaluate to a scalar`

The correct code should be:
`if ( any( gamma != float3(1., 1., 1.) ) )`

This is essentially the same issue as #1810 but for HLSL. There's already a fix in `GpuShaderText::vectorCompareExpression()` but it's only for Metal.

Can be reproduced using the OCIO config shipped with recent Blender versions, with some of the AgX looks. In our case we're creating a LegacyViewingPipeline containing a DisplayViewTransform and a looks override, similarly to the ociodisplay app.