The L10n bot change https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikimediaCampaignEvents/+/1083730 had to be manually reviewed because the message translation included a <page-collection> tag, which is unrecognized by Jenkins job configuration. Copying the error here because they are auto-deleted after some time:
03:27:55 + contains_disallowed_html log/additions.txt 03:27:55 + cat log/additions.txt 03:27:55 + sed -E -e 's/<\/? ?(abbr|b|bdi|big|br|charinsert|citation|code|dd|del|div|dl|dt|em|h1|h2|h3|h4|hr|i|kbd|li|mark|math|NDL|nowiki|ol|p|page|pagelist|pages|pre|ref|samp|small|span|strong|sub|sup|syntaxhighlight|templatedata|templatestyles|tt|u|ul|user|var)( ((alttext|class|dir|display|id|lang|title|xml:lang|xmlns)=\\?["'\''][^=<>"'\'']*\\?["'\'']))* ?\/?>//g' -e 's/<!--//g' -e 's/<https?:\/\/[a-zA-Z0-9./-]*>//g' 03:27:55 + grep '<' 03:27:55 + "page-collection-tracking-category-desc": "<page-collection> ehtiva edən səhifələr" 03:27:55 + "page-collection-tracking-category-desc": "Páginas que contienen un marcador <page-collection>.", 03:27:55 + "page-collection-tracking-category-desc": "דפים שמכילים סמן <page-collection>", 03:27:55 + "page-collection-tracking-category-desc": "Страници што содржат обележувач <page-collection>", 03:27:55 + "page-collection-tracking-category-desc": "Pagina’s met een markering <page-collection>", 03:27:55 + "page-collection-tracking-category-desc": "Странице које садрже <page-collection> маркер" 03:27:55 + echo 'HTML detected. Manual review required' 03:27:55 HTML detected. Manual review required 03:27:55 + exit 1
The easy solution appears to be to replace <code><nowiki><page-collection></nowiki></code> with <page-collection>.