[Proposal] Add Entity SIG approvers for Entity specification work.

[jsuereth]

Generally, our direction for specification sponsorship is to promote general approvers of the specification (see #3821).

This change proposes having a set of Entity (and Resource) specification approvers from the Entities SIG. The intention is to give the active specification work this SIG is doing a clear indication of expertise and ownership within OpenTelemetry.

The intention is that this role will be folded back into general Specification Sponsorship role once Entities has completed its work.

• Phase 1 is resource + entity work. Approval on resource specification would be removed post Phase 1 for general spec sponsors. At the completion of Phase 1, it is expected that this approver group can be removed and some Entity approvers may be promoted to Spec Sponsor.
• Phase 2 for entities would be a new project proposal. If this project is accepted, we could then re-create an entity only approver delimination in the specification for the same reason.

This is a proposal to give a clear signal to Specification Maintainers the approval status of PRs coming from the Entities SIG (green check marks and clear ownership of those).

Changes

Please provide a brief description of the changes here.

For non-trivial changes, follow the change proposal process.

• Related issues #
• Related OTEP(s) #
• Links to the prototypes (when adding or changing features)
• CHANGELOG.md file updated for non-trivial changes
• spec-compliance-matrix.md updated if necessary

[dyladan]

Why is this in draft?

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 7 days.

[github-actions]

Closed as inactive. Feel free to reopen if this PR is still being worked on.