Remove group-ping from fe-maintainer template

Why is this change being made?

When using this template I was a bit surprised by the ping to the whole group, which happened as soon as the MR got created.

Since I didn't have all the content for the description ready, I felt a bit pressured to quickly write something up. I can imagine that it also created some extra noise for the group's members.

I think it would be a better experience for both the author and maintainers to only create the ping once the MR is ready to be reviewed 🙂

Author Checklist

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
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  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the Maintained by section on the page being edited
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies
• If the changes affect team members, or warrant an announcement in another way, please consider posting an update in #whats-happening-at-gitlab linking to this MR
  • If this is a change that directly impacts the majority of global team members, it should be a candidate for #company-fyi. Please work with internal communications and check the handbook for examples.

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