Replace get_blog_details() usage in wpmu_delete_blog() with get_site( $blog_id )

[flixos90]

See #37102

[iamfriendly]

Replaced get_blog_details() with get_site() in wpmu_delete_blog()

[iamfriendly]

In 38346.diff, Replaced get_blog_details() with get_site() in wpmu_delete_blog()

[jeremyfelt]

In 38821:

Multisite: Replace get_blog_details() usage in wpmu_delete_blog() with get_site().

Props spacedmonkey, iamfriendly.
See #37102.
Fixes #38346.