Delete prepareLegacyRequest function in drupal 9

[John-doe-lee]

[devkinetic]

One year anniversary coming up... would be great to get this merged.

[bobemoe]

Just updated to Drupal9 and needed this among other patches for console.

https://github.com/hechoendrupal/drupal-console/pull/4269.patch wouldn't apply as it failed to patch composer.json, not sure why the .patch link is showing 3 changed files when "Files Changed" above shows only 1 DrupalApi.php changed. I extracted that part to a local patch and it applies fine.

[LOBsTerr]

it is already there https://github.com/hechoendrupal/drupal-console/blob/master/src/Utils/DrupalApi.php#L269

Thank you for your contribution