Bump gitlab-mail_room to 0.0.7

What does this MR do?

Bumps gitlab-mail_room to 0.0.7, which incorporates an upstream change required by a customer.

Related issues

• Original issue: https://gitlab.com/gitlab-org/gitlab-mail_room/-/issues/15
• Upstream fix: https://github.com/tpitale/mail_room/pull/114
• Mirror commit: https://gitlab.com/gitlab-org/gitlab-mail_room/-/commit/b0136693b9f0d869a8ddbd59412556d0c47380fd
• 0.0.7 Release: https://gitlab.com/gitlab-org/gitlab-mail_room/-/issues/16
• Version bump in gitlab-org/gitlab: gitlab-org/gitlab!44882 (merged)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Integration tests added to GitLab QA
• The impact any change in container size has should be evaluated