Remove Engineering Allocation for DB team

Why is this change being made?

When the 100% engineering allocation for the Database team was initially made, the DB was under heavy operational load and the team did not have a dedicated product manager. Since then:

• The team completed crucial EA work such as addressing PK overflow risk
• The team has a dedicated product manager
• The DB stability work they are currently focused on is aligned with the product roadmap. See the 14.10 planning issue as an example.

This MR aims to reflect the current status of the team and signal that an engineering allocation is no longer needed since the reliability and stability improvements the team is working on is driven by both product and engineering.

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
  • Copy/paste the Slack conversation to document it for later, or upload screenshots. Verify that no confidential data is added.
• Assign reviewers for this change to the correct DRI(s)
  • 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 in 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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