Bundled themes: Version bumps for version 7.0.

This bumps the version for the upcoming release WordPress 7.0.
Twenty Ten: 4.6.
Twenty Eleven: 5.1.
Twenty Twelve: 4.8.
Twenty Thirteen: 4.6.
Twenty Fourteen: 4.5.
Twenty Fifteen: 4.2.
Twenty Sixteen: 3.8.
Twenty Seventeen: 4.1.
Twenty Nineteen: 3.3.
Twenty Twenty: 3.1.
Twenty Twenty-One: 2.8.
Twenty Twenty-Two: 2.1.
Twenty Twenty-Three: 1.6.
Twenty Twenty-Four: 1.5.
Twenty Twenty-Five: 1.5.

Props sabernhardt, shailu25, audrasjb.
Fixes #64817.


git-svn-id: https://develop.svn.wordpress.org/trunk@62344 602fd350-edb4-49c9-b593-d223f7449a82