chore: remove unused contact links from issue template

[divyanshub024]

Summary

Screenshots

Before	After

How this was verified

Checklist

• flutter analyze lib and flutter analyze in example/ and playground/ are clean
• dart format . applied
• Exercised in the playground — with a stage demo added or updated if this is a new component or variant
• No new entries under dependencies: in pubspec.yaml (Flutter SDK and flutter.dev packages only)
• Nothing model-facing — no prompts, schemas, or provider/network calls
• New public API is exported from lib/flow_ui.dart and documented in docs/ and the README table
• CHANGELOG.md updated for user-facing changes, with breaking changes called out
• PR title follows conventional commits (feat:, fix:, refactor:, docs:, chore:)

---

Note

Low Risk
GitHub issue-form metadata only; no application, security, or runtime behavior changes.

Overview
Removes the GitHub issue contact_links (docs, playground, roadmap, API reference) from .github/ISSUE_TEMPLATE/config.yml, leaving only blank_issues_enabled: true.

^{Reviewed by Cursor Bugbot for commit 03a6f05. Bugbot is set up for automated code reviews on this repo. Configure here.}