Embed the version of ACE of GitHub (83e8b60) and remove the marks of its fixed bugs

[szczepanskiNicolas]

The ACE embedded in PyCSP3 (pycsp3/solvers/ace/ACE-2.6.jar, 58c2393 of 2026-09-03) is replaced by the jar built from the master branch of xcsp3team/ACE (commit 83e8b60 of 2026-10-08, ./gradlew build, Java 21; no new release since 2.6, and the version displayed is still ACE v2.6). This version fixes the bugs of ACE found by the unit tests: xcsp3team/ACE#11, #16, #18, #20, #21, #22, #23, #24 and #25.

Commit	Change
a6351de	the new jar
a85e5e1	the marks of the 33 tests of these bugs are removed (they were strict xfail, so they failed as XPASS with the new jar); the parameter request of the tests that no longer mark a bug is removed

ACE issue	Tests whose mark is removed
xcsp3team/ACE#11 (AllDifferent with a single-value domain)	2
xcsp3team/ACE#16 (allDifferent-matrix, non-square matrix)	3
xcsp3team/ACE#18 (notAllEqual on two variables)	6
xcsp3team/ACE#20 (lex with a single remaining position)	4
xcsp3team/ACE#21 (precedence with covered)	5
xcsp3team/ACE#22 (sum with notin)	7
xcsp3team/ACE#23 (sum whose terms cancel out)	3
xcsp3team/ACE#24 (count with (ne,0) or (ne,|X|))	2
xcsp3team/ACE#25 (count with several values and (eq,0))	1

Tests (Python 3.13.7):

• whole suite with the new jar, before removing the marks: 8020 passed, 203 skipped, 428 xfailed, and 33 failed, all [XPASS(strict)] with the marks above; the passed tests are the same as with the previous jar (no regression);
• after removing the marks: the 33 tests pass, and the modified tests (all the solvers): 404 passed, 8 skipped, 30 xfailed.

The bugs of ACE still open (xcsp3team/ACE#12, #14, #15, #17) still fail with the new jar, as well as the failure of ACE (parser) on a table with an empty set of supports (the constraint false).