Clear RuboCop violations on anchors.rb

Clear the following RuboCop violations on anchors.rb:

• https://docs.rubocop.org/rubocop/cops_lint.html#lintpercentstringarray
• https://docs.rubocop.org/rubocop-performance/cops_performance.html#performancecollectionliteralinloop
• https://docs.rubocop.org/rubocop/cops_style.html#stylepercentliteraldelimiters

CC @ashrafkhamis @claytoncornell @jglassman1 @lciutacu @phillipwells @drcatherinepope just FYI.