Move pipeline specs from 6_release/ to 4_verify/

What does this MR do and why?

Describe in detail what your merge request does and why.

Moving pipeline specs from 6_release/ to 4_verify/ per discussion #354797 (comment 903268735) .

Test cases to be archived after merge:

• https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/348093 - gitlab-org/quality/testcases#2030 (closed)
• https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/348094 - gitlab-org/quality/testcases#2029 (closed)
• https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/348092 - gitlab-org/quality/testcases#2054 (closed)
• https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/348091 - gitlab-org/quality/testcases#2117 (closed)
• https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/348032 - gitlab-org/quality/testcases#2225 (closed)

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