fix: #3637144 Break stale content locks on edit

Stale content locks never expire: Varbase Core's content_lock.settings.yml has no timeout, so it overwrites Content Lock 3's default with NULL.

Issue: https://www.drupal.org/i/3637144

• Add timeout: 1800 to config/optional/content_lock.settings.yml.
• Stop installing the deprecated Content Lock Timeout, drop its settings and Ultimate Cron job.
• varbase_core_update_90011 sets the timeout to 1800 when empty and uninstalls Content Lock Timeout when enabled.

Local pipeline (gitlab-ci-local) green: composer, composer-lint, phpcs, phpstan, eslint, cspell, varbase-e2e-test.

Remaining

• Run drush updb on an existing site, and a fresh install.
• Confirm re-enabling expiry is fine for sites that cleared the timeout on purpose.

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