chore(deps): move the train and the consumer smokes onto one set of versions

[DemchaAV]

Replaces #565, #566, #567, #568, #569, #570, #571, #572 and #573.

Why

The release push made Dependabot rescan, and it opened nine pull requests. Eight are the
same bump — junit-jupiter 5.11.4 → 6.1.3 in each consumer-smoke project, one per manifest
because the group covers minor and patch and this is a major. The ninth carries everything
else. Taken together they are one change.

One of them was already stale when it opened. It proposed <gc.version> 2.0.0 → 2.1.1
in the consumer poms, and 2.2.0 has been on Central since the cut.

What changed

The train — junit-bom 6.1.2 → 6.1.3 and logback-classic 1.6.1 → 1.6.2 wherever they
are pinned (core, qa, templates, testing, render-pdf/docx/pptx, examples, benchmarks), and
the Maven wrapper to 3.9.16.

The consumer projects — junit-jupiter 5.11.4 → 6.1.3, surefire 3.5.2 → 3.5.6, and
enforcer 3.5.0 → 3.6.3 in s2. They were two majors behind the JUnit the rest of the
repository runs.

Their <gc.version> → 2.2.0, not 2.1.1. That property is the version each project
verifies when the runner names none. The release step moves the same default in run.sh,
run.ps1, the workflow input and the README — and never reached the poms. Every runner does
pass a version, so the fallback decides nothing on a normal run, which is how it stayed two
releases behind without a single run going red.

So the release step finds the consumer projects rather than listing them. They arrive one
per published coordinate combination, so the set grows when a coordinate does, and a list in
the script would be a second place to remember that.

And a guard holds the default in one place. VersionConsistencyGuardTest now reads all
eleven — the two runners, the workflow input, and each pom's <gc.version> — and holds them
to acceptableTargets(), the published-release rule the install snippets already follow.

mvnw.cmd is left alone: the offered change rewrote the whole file for its line endings,
while what the wrapper upgrade needs is the distributionUrl.

Tests

The consumer harness, which is what a JUnit major actually risks —
bash scripts/release-smoke/run.sh → 8 of 8 BUILD SUCCESS, exit 0. Each project builds
in an isolated local repository with the cache evicted, so the coordinates were resolved from
Central rather than from anything this machine had lying around.

./mvnw -B -ntp clean verify → BUILD SUCCESS, no failures.

The new guard was driven from the files in three broken states, each red, and green on
the tree as it stands: one pom left on the previous release, a runner naming a version nobody
published, and a pom that stops declaring the property at all — that last one names the file
rather than silently skipping it.

The release step's discovery was dry-run against a copy of the tree: it finds all eight
consumer poms and moves each fallback with the release.