Update terminology in test description from completion spec

[JuanitoFatas]

This Pull Request updates terminology in the codebase: restricted is easier to understand and less offensive.

Original motivation, other community efforts examples:

• [ci skip] change all instances of blacklist and whitelist to denylist… rails/rails#33681
• deserialize_jsonapi not found on controller graphiti-api/graphiti#10
• Finish converting whitelist and blacklist references rails/rails#33718
• Use friendlier terminology in YAML.safe_load ruby/psych#378
• Use friendlier terminology in rubysocket.h ruby/ruby#2008
• Use friendlier terminology in _leaf_helpers.erb ruby/ruby#2009
• Use permitted in line_length.rb rubocop/rubocop#6464
• Update friendlier terminology in Gem::SafeYAML rubygems/rubygems#2463
• Update terminologies dtao/safe_yaml#93
• Introduce Request::ALLOWED_SCHEMES and deprecate existing constant rack/rack#1314
• Update terminology in http_status.rb rubocop/rubocop#6466
• Update terminology in rails/validation.rb rubocop/rubocop#6467
• Update terminology in BUILD_DETAIL.md rspec/rspec-core#2576
• Update terminology in BUILD_DETAIL.md rspec/rspec-expectations#1083
• Update terminology in BUILD_DETAIL.md rspec/rspec-mocks#1246
• Update terminology in BUILD_DETAIL.md rspec/rspec-support#356
• Use safelist(s), allowlist(s) where applicable flavorjones/loofah#158
• Use clearer terminologies #1874

[JuanitoFatas]

Test failure seems unrelated:

Failures:

  1) show-doc should work even if #call is defined on Symbol
     Failure/Error: Symbol.instance_eval { define_method(:call, call_method) } if call_method
     
     TypeError:
       wrong argument type NilClass (expected Proc/Method)
     # ./lib/pry/command.rb:444:in `block in use_unpatched_symbol'
     # ./lib/pry/command.rb:444:in `use_unpatched_symbol'
     # ./lib/pry/command.rb:433:in `call_safely'
     # ./lib/pry/command.rb:371:in `process_line'
     # ./lib/pry/command_set.rb:365:in `process_line'
     # ./lib/pry/pry_instance.rb:407:in `process_command'
     # ./lib/pry/testable/pry_tester.rb:24:in `block in eval'
     # ./lib/pry/testable/pry_tester.rb:17:in `eval'
     # ./lib/pry/testable/evalable.rb:13:in `pry_eval'
     # ./spec/commands/show_doc_spec.rb:24:in `block in <main>'

Finished in 21.1 seconds (files took 1.73 seconds to load)
1194 examples, 1 failure, 2 pending

Failed examples:

rspec ./spec/commands/show_doc_spec.rb:22 # show-doc should work even if #call is defined on Symbol

[kyrylo]

This change should've probably been in #1874.