Migrate demo to Next 14.0.3 and next-intl 3.2.2

[stepan662]

Hey @juanillo62gm, thanks for the contribution. This is just a dummy repo, where the example apps are copied after each release. The actual code is in our monorepo, so I've used your changes and applied them (with some more upgrades) https://github.com/tolgee/tolgee-js/pull/3287

[juanillo62gm]

Great, closing this one