Be more strict about heredocs
I tend to be strict about heredocs, so I propose to activate the following Perl::Critic policies:
- https://metacpan.org/pod/Perl::Critic::Policy::ValuesAndExpressions::ProhibitSpecialLiteralHeredocTerminator
- https://metacpan.org/pod/Perl::Critic::Policy::ValuesAndExpressions::RequireQuotedHeredocTerminator
- https://metacpan.org/pod/Perl::Critic::Policy::ValuesAndExpressions::RequireUpperCaseHeredocTerminator
A quick check showed 58 violations, almost all of them about ValuesAndExpressions::RequireQuotedHeredocTerminator.