[repo] Problem with Push migated pages to Wikimedia GHA

What is the issue that you're experiencing?

After merging https://github.com/moodle/devdocs/pull/200, the Push migated pages to Wikimedia GHA started failing: https://github.com/moodle/devdocs/actions/runs/8827507626/job/24247452474#logs with the following error:

info: Starting update of migrated pages in remote site
/home/runner/work/devdocs/devdocs/scripts/utils.js:63
    articleData.newDocIds = Array.from(articleData.data.matchAll(docRegexp))
                                                        ^

TypeError: Cannot read properties of undefined (reading 'matchAll')
    at /home/runner/work/devdocs/devdocs/scripts/utils.js:63:57
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async /home/runner/work/devdocs/devdocs/scripts/utils.js:322:33
    at async Command.<anonymous> (/home/runner/work/devdocs/devdocs/scripts/wikimedia-sync.js:67:9)

That's probably related to the fact that this page was migrated into an existing page and now /general/community/contribute.md has a duplicated entry in migratedPages.yml.

Are you able to provide a patch for this?

None

Start with the failing Wikimedia workflow run and inspect scripts/utils.js at line 63, then follow its call from scripts/wikimedia-sync.js at line 67. Check migratedPages.yml, especially the duplicated /general/community/contribute.md entry, and verify that the migration data is defined and the workflow completes successfully.