Removes deprecations in readiness from Drupal 9.
Change log:
* 71beecf: Issue #309835 by Deeksha B: Missing configure button in module listing page - DeekshaPrabhuB
* f312810: Issue #3022799 by mahtab_alam: t() calls should be avoided in classes use $this->t() - mahtab12
* 0fc9af3: Issue #3109358 by kim.pepper, mahtab_alam, webapp's: Remove use of deprecated pager - kimpepper
* 6fb5ac7: Issue #3109386 by kim.pepper: Add core_version_requirement to allow installation on D9 - kimpepper
