addons-frontend: ChunkLoadError: Loading chunk XX failed (during add-on installation)

There are a lot of errors like below since the last push.

https://sentry.prod.mozaws.net/operations/addons-frontend-amo-prod/issues/6015921/

ChunkLoadError: Loading chunk 49 failed.
(error: https://addons-amo.cdn.mozilla.net/amo-i18n-pl-5895ff0e3199834fe71a.js)
  at location (./src/locale/fr/amo.js?0bc5:7:1)
  at __webpack_require__ (./src/amo/components/LanguagePicker/index.js:36:28)
  at e/< (./src/amo/components/LanguagePicker/index.js:36:13)
  at G (./src/amo/utils/errors.js:14:14)
  at a (./src/amo/components/LanguagePicker/index.js:57:14)
...
(16 additional frame(s) were not displayed)