[cleanup] remove stale presubmit template

[pq]

The template's been stale for a bit. Removing to avoid future confusion.

---

Review the contribution guidelines below:

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.
• I've included the required information in the description above.
• My up-to-date information is in the AUTHORS file.
• I've updated CHANGELOG.md if appropriate.

Contribution guidelines:

• See
  our contributor guide and
  the Flutter organization contributor guide
  for general expectations for PRs.
• Larger or significant changes should be discussed in an issue before creating a PR.
• Dart contributions to our repos should follow the Dart style guide and use
  dart format.
• Java and Kotlin contributions should strive to follow Java and Kotlin best
  practices (discussion).

[gemini-code-assist]

Note

Gemini is unable to generate a review for this pull request due to the file types involved not being currently supported.

[auto-submit]

autosubmit label was removed for flutter/flutter-intellij/8979, because - The status or check suite checker (VERIFY_BOT) has failed. Please fix the issues identified (or deflake) before re-applying this label.