Draft: Fix 'ArgumentError: invalid byte sequence in US-ASCII' error

ruby-pry-byebug fails to build with the below error,

Backtrace command#test_0001_shows a backtrace:
ArgumentError: invalid byte sequence in US-ASCII
    /usr/src/packages/BUILD/test/commands/frames_test.rb:70:in `split'
    /usr/src/packages/BUILD/test/commands/frames_test.rb:70:in `block (2 levels) in <class:FramesTest>'

Set the string encoding to UTF-8 to fix this error.

Fixes: https://phabricator.apertis.org/T9330