Remove "core: 8.x" from the .info.yml file

Hello Maintainers,
I have provided a patch to fix this issue.
Please review it.

Thanks!

Raveen Thakur → made their first commit to this issue’s fork.

Closing in favor of 3287186 which has already been RTBCed

Modules, themes. and profiles are allowed to use the following lines in their .info.yml file.

core: 8.x
core_version_requirement: ^8 || ^9

That is described in New 'core_version_requirement' key in info.yml files for modules, themes and profiles → allows Composer semantic version constraints including specifying multiple major versions of core, which states:

For example a module that is compatible with Drupal 8 and Drupal 9 can have a info.yml file like this

name: My Module
type: module
core: 8.x
core_version_requirement: ^8 || ^9

There is no change that must be done in that .info.yml file.