tests: Use "no plan" style of TAP output

[smcv]

• tests: Use "no plan" style of TAP output

  Similar to
  flatpak/flatpak@b1fdf6c
  this makes it more obvious where the boundary between test-cases is,
  and similar to tests: Don't specify planned number of tests up-front flatpak#6794 it avoids
  needing to declare up-front how many tests we plan to run (which makes
  conflicts inevitable if we add more than one test to the same script).

[bbhtt]

LGTM minus the JXL change in appstream as I said in the other thread.

If you want this merged first, you can drop the JXL change.

I'll have to do some changes to the code to make sure it stays PNG and release a new version.

[smcv]

I moved the most important part of this for diagnosing #776 into #781.

Because the number of tests in test-builder.sh has changed between flatpak-builder-1.4.x and main, it's not going to be useful to rebase tests: Use "no plan" style of TAP output onto main until the two branches have been reconciled.

[bbhtt]

Are you going to rebase this? or should I take over? It's the last thing before the 1.4.12 release.

[smcv]

This will need a rebase after #782 lands, but is otherwise ready (only look at the last commit).

This also doesn't have to be a release blocker, skipping it until after 1.4.12 is completely fine.

I've targeted main only here: I don't know whether you'll want it in 1.4.x or not. If cherry-picked to 1.4.x, there will be some conflicts in places where main has added additional test coverage (just test-builder.sh, I think).

[smcv]

eaa42a1: rebased after #782 landed, no functional change.

[bbhtt]

Yep I am backporting it to 1.4.x