[Chapel Merge] Adjust spec for member -> contains deprecation

Branch: refs/heads/master
Revision: 323378e
Author: mppf
Log Message:

Merge pull request #16558 from mppf/spec-member-contains

Adjust spec for member -> contains deprecation

.member has been deprecated for several releases now - this updates the spec to match.

Trivial and not reviewed.

Modified Files:
M doc/rst/language/spec/domains.rst
M doc/rst/language/spec/ranges.rst

Compare: https://github.com/chapel-lang/chapel/compare/c834b64d42bf...323378e5f05e