Build : Update Arnold version used for CI builds
Build : Update Arnold version used for CI builds

Build
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 - Arnold : Updated to version 6.0.1.0 (#3585)

johnhaddon/gaffer,andrewkaufman/gaffer,hradec/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,boberfly/gaffer,lucienfostier/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,boberfly/gaffer,appleseedhq/gaffer,andrewkaufman/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,hradec/gaffer,ImageEngine/gaffer,hradec/gaffer,appleseedhq/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,lucienfostier/gaffer,boberfly/gaffer,ImageEngine/gaffer,boberfly/gaffer,lucienfostier/gaffer,GafferHQ/gaffer,appleseedhq/gaffer,appleseedhq/gaffer,ImageEngine/gaffer,hradec/gaffer,johnhaddon/gaffer,hradec/gaffer,lucienfostier/gaffer