Remove unusable asciidoc attribute

[etomzak]

I think the intent here is to provide a plural alias for the work-item glossary term. Since this attribute is defined at the very end of the spec, though, it's not used anywhere and not usable anywhere.

If this alias is needed, then it needs to be defined somewhere like adoc/config/attribs.adoc.

[CLAassistant]

All committers have signed the CLA.

[keryell]

Thanks.
But as you suggest, perhaps a solution is to advertise more adoc/config/attribs.adoc and its neighborhood and put this definition there instead of being at the beginning of adoc/syclbase.adoc?

[gmlueck]

Merging this as editorial.