Update mtimoustafa fe maintainer of CustomersDot

Manager Justification

It's hard to specify hard requirements for becoming a maintainer, which is why the documentation consists of flexible guidelines. Reviewers are encouraged to think of their eligibility for maintainership in the terms of "I could be ready at any time to be a maintainer as long as it is justified".

• The MRs reviewed by the candidate consistently make it through maintainer review without significant additionally required changes.
• The MRs authored by the candidate consistently make it through reviewer and maintainer review without significant required changes.

• Mohamed has reviewed ~23 MRs frontend merge requests within the CustomersDot repository. However Mohamed has reviewed additional front end MRs that were not tagged with the frontend label, and has compiled a list of MRs reviewed in a google sheet. Within that sheet Mohamed has called out as notable the reviews he's most proud of.

• Mohamed has authored ~8 MRs frontend merge requests within the CustomersDot repository.

• Mohamed has been a frontend and backend reviewer for customers-gitlab-com for 1 year

Before Merging (Manager Tasks)

• Close any relevant trainee maintainer issues with a comment indicating that this merge request is being created, as (they are no longer required to become a maintainer).
• Mention the maintainers from the given specialty and ask them to provide feedback to the manager directly.
• Leave this merge request open for 1 week, to give the maintainers time to provide feedback.
• Ensure we have at least 2 approvals from existing maintainers.

Once This MR is Merged

1. Create an access request for maintainer access to gitlab-org/<project>.
2. Join the [at]frontend-maintainers slack group
3. Ask the maintainers in your group to invite you to any maintainer-specific meeting if one exists.
4. Let a maintainer add you to gitlab-org/maintainers/frontend with Owner access level.
5. Announce it everywhere
6. Keep reviewing, start merging 🤘 😎 🤘