chore: remove repo-level PR template

[jamesnrokt]

Why

This repo carries its own .github/PULL_REQUEST_TEMPLATE.md, which GitHub prefers over the org-wide default template published in mParticle/.github. That means new PRs here silently skip the shared template every other @mParticle/sdk-team-owned repo is meant to use. Once this lands, opening a new PR here shows the same org-wide template contributors see everywhere else.

Programme

Standalone change, no programme.

What changes

Deletes .github/PULL_REQUEST_TEMPLATE.md. Also updates AGENTS.md, which pointed contributors and agents at that file by path — it now points at the org-wide default instead, so it doesn't dangle once the file is gone. New PRs opened against this repo now fall back to the org-wide default at mParticle/.github (.github/PULL_REQUEST_TEMPLATE.MD).

Linked work

None.

Rollout

Nothing changes in production; if this is wrong, revert the pull request.

Risks

• Nothing can break beyond the text itself.

Risk class: low.

Who

Written by: automated coding agent (Claude Code), on behalf of the requesting engineer — standalone repo-hygiene request, no linked ticket.
Code reviewed before opening: an independent review agent, before the commit was made.
Design reviewed before opening: no one.
Decision this implements: a repo-hygiene request from the repo owner to drop this repo's PR template override so it falls back to the org-wide default. No ticket, no linked record.
Checked: confirmed no file under .github/workflows/ references PULL_REQUEST_TEMPLATE; confirmed mParticle/.github publishes an org-wide default template; confirmed AGENTS.md was the only other file referencing the deleted path.
Not checked: nothing else touched, nothing else to check.

Size

Hand-written: 1 line added, 29 lines removed, 1 file deleted, 1 file changed.
Generated: none.

[cursor]

PR Summary

Low Risk
Documentation and template changes only, with no impact on SDK code or build pipelines.

Overview
Removes the repository-level .github/PULL_REQUEST_TEMPLATE.md so new pull requests fall back to the org-wide default template published at mParticle/.github.

Updates developer guidance in AGENTS.md to reference the organization-wide default template.

^{Reviewed by Cursor Bugbot for commit d8253c8. Bugbot is set up for automated code reviews on this repo. Configure here.}