Revert canonical order enforcement for position-try-fallbacks
in WPT tests.
<try-tactic>
is in fact order-dependent 1:
Given inline-start & end, block-start & end: 1 & 2, a & b:
flip-start
: a & 2, 1 & bflip-inline
: 2 & a, 1 & b
And
flip-inline
: 2 & 1, a & bflip-start
: a & 1, 2 & b
Are not equal.
Differential Revision: https://phabricator.services.mozilla.com/D222114
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1918670
gecko-commit: bf6dffc72a3452c98966164125201d146187ca35
gecko-reviewers: firefox-style-system-reviewers, emilio