#1689: fix set -e masking test failures in Makefile

[VasilevNStas]

Closes #1689

Fix set -e masking test failures in Makefile. The test and entry targets used echo "$$?" > target/*.exit after the command, but set -e causes the shell to exit before echo runs if the command fails (nonzero exit). Now uses || rc=$$? to capture the exit code without triggering the errexit trap.

Changes:

• test target: save docker exit code via || rc=$$? pattern
• entry target: same pattern for action test script

[VasilevNStas]

@yegor256 plz review

[yegor256]

@VasilevNStas why do we need ; \? it's ONESHELL, should work without this

[VasilevNStas]

Fixed — removed ; \ since Makefile uses .ONESHELL. Thanks for the note!

[VasilevNStas]

@yegor256

Both CI failures are pre-existing and unrelated to this PR:

1. test_some_pull_hoc_size_handles_nil_additions_or_deletions — needs Jp.qoreset before calling Jp.qosearch. Fixed in PR #1667: guard Time.parse(ENV[TODAY]) against empty/invalid values #1819 (branch 1667-today-empty).

2. NoMethodError: list_milestones in FakeOctokit — the milestone-was-set judge calls Fbe.octo.list_milestones which is not implemented in FakeOctokit. The patch was in branch 1724-nil-time-arithmetic (PR #1724 nil guard for time arithmetic in code-was-reviewed #1809) but that PR was closed due to mixed content. Needs a fresh PR.