fix(VDataTable): typo that cause watcher triggered twice

[mdunisch]

Fix typo to that the page is mutated instead of the value of the emit.

Description

There was a typo (page.value instead of needed value.page) that triggered the watcher twice instead of changing the emit value.

fixes #21555

[J-Sek]

I think the pagination is broken now.
Table does not go back to the first page.