Remove ServiceInsight references

[kylierozegnal]

• https://github.com/Particular/GeneralPlatformExperience/issues/3559
• RFC : https://github.com/Particular/GeneralPlatformExperience/pull/3698

As part of the above issue, this PR removes references to SI

Change type

• Tiny mistakes or improvements that don't change the content or meaning
• A small decision according to the decision-making guidelines
  • (Not required for decisions made by task forces) Decision type has been verified by someone not directly involved in the change being made in order to avoid bias.
  • (Not required for decisions made by task forces) The person verifying the decision type must LEAVE A COMMENT on this PR stating they approve the decision type. This does not imply agreement with the change, but only that the change type is correct. Sample comment: "Decision type has been verified as a small decision"
  • The PR has been approved by a reviewer who is not also the small decision verifier
  • Consider, is there some automation or other process that will make the necessary people aware of this at the appropriate time? If so, no announcement is needed. Otherwise, after the PR is merged, announce it in the relevant channel (e.g. in #staff-success or, if absolutely all staff should see it, in #announcements) and ping all the impacted parties.
• A decision requiring an RFC but not a task force.
• An RFC created by a task force
• Documentation update
• Other:

[kylierozegnal]

After speaking with the Platform Internals squad, it has been decided that since we are not deprecating, and we still have SI in our docs, and users can still create bugs and issues in SI, we should not move forward with this PR