Cannot create pages if parent page ends with a dot

Steps to reproduce:

1. Create a page with the name "This is a sentence." (or just "1.")
2. Save the page and in view mode click on "Create" again
3. For the subpage enter any valid title / name and click on "Create"

Expected behavior: Edit mode of new page appears

Actual behavior: the Parent / Name form appears with a note that the space reference is not valid.

The workaround is to rename the parent page name manually so it does not end with a dot (and maybe disallow dots on page names in the wiki administration, page naming strategies).

This might have been introduced in XWIKI-24031; the regex in https://github.com/xwiki/xwiki-platform/commit/68af971c340985d0e8a688264c619f9cb6eb0f58#diff-5694a4e0e079683deae504a02a7bb3f4251f698f9649bb05e02ead4f2fc38b33R401  applies only to the space name, but not the page name when creating (non-terminal) pages.