Replaces Removals URL with Deprecations URL

Why is this change being made?

We have simplified our deprecations and removals documentation pages such that share the same view, and, as such, the removals URL has been retired and redirected to deprecations.html.

This MR updates the release post template to replace the link for removals documentation with the canonical deprecations URL.

Author and Reviewer Checklist

Please verify the check list and ensure to tick them off before the MR is merged.

• 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
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  • The when to get approval handbook section explains the workflow in more detail
• For transparency, share this MR with the audience that will be impacted.
  • Team: For changes that affect your direct team, share in your group Slack channel
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