Perl::Critic::Policy::InputOutput::RequireEncodingWithUTF8Layer(3pm) on Linux
The text b253c7ef1959, as Debian 12 (Bookworm) shipped it.
Write "open $fh, q{<:encoding(UTF-8)}, $filename;" instead of "open $fh, q{<:utf8}, $filename;".
Perl::Critic::Policy::InputOutput::RequireEncodingWithUTF8Layer(3pm) on Linux now