Remove `if-dot-com-gitlab-org-and-security-merge-request-manual-ff-package-and-e2e` condition from rules

The following discussion from !144864 (merged) should be addressed:

• @rymai started a discussion:

  observation: The rule is as follows but I couldn't find any reference to $QA_MANUAL_FF_PACKAGE_AND_QA! It seems the variable was introduced by !74349 (merged) (cc @mlapierre):

  Note: I've set QA_MANUAL_FF_PACKAGE_AND_QA to true in CI/CD settings so that the jobs are manual until we're ready to respond if there are problems when they're made automatic. Task tracking https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1094

    if: '$CI_SERVER_HOST == "gitlab.com" && $CI_PROJECT_NAMESPACE =~ /^gitlab-org($|\/security$)/ && ($CI_MERGE_REQUEST_EVENT_TYPE == "merged_result" || $CI_MERGE_REQUEST_EVENT_TYPE == "detached") && $QA_MANUAL_FF_PACKAGE_AND_QA'

  We should delete the if-dot-com-gitlab-org-and-security-merge-request-manual-ff-package-and-e2e condition entirely as a follow-up.