Merge branch 'ps/test-wo-perl-prereq'

Merge branch 'ps/test-wo-perl-prereq'

"make test" used to have a hard dependency on (basic) Perl; tests
have been rewritten help environment with NO_PERL test the build as
much as possible.

* ps/test-wo-perl-prereq:
  t5703: refactor test to not depend on Perl
  t5316: refactor `max_chain()` to not depend on Perl
  t0210: refactor trace2 scrubbing to not use Perl
  t0021: refactor `generate_random_characters()` to not depend on Perl
  t/lib-httpd: refactor "one-time-perl" CGI script to not depend on Perl
  t/lib-t6000: refactor `name_from_description()` to not depend on Perl
  t/lib-gpg: refactor `sanitize_pgp()` to not depend on Perl
  t: refactor tests depending on Perl for textconv scripts
  t: refactor tests depending on Perl to print data
  t: refactor tests depending on Perl substitution operator
  t: refactor tests depending on Perl transliteration operator
  Makefile: stop requiring Perl when running tests
  meson: stop requiring Perl when tests are enabled
  t: adapt existing PERL prerequisites
  t: introduce PERL_TEST_HELPERS prerequisite
  t: adapt `test_readlink()` to not use Perl
  t: adapt `test_copy_bytes()` to not use Perl
  t: adapt character translation helpers to not use Perl
  t: refactor environment sanitization to not use Perl
  t: skip chain lint when PERL_PATH is unset