chore: add 6.2 to and remove 6.0 and 4.0 from pr template (pingcap#8973)

.github/pull_request_template.md

@@ -19,14 +19,13 @@ By default, **CHOOSE MASTER ONLY** so your changes will be applied to the next T
 For details, see [tips for choosing the affected versions](https://github.com/pingcap/docs/blob/master/CONTRIBUTING.md#guideline-for-choosing-the-affected-versions).
 
 - [ ] master (the latest development version)
+- [ ] v6.2 (TiDB 6.2 versions)
 - [ ] v6.1 (TiDB 6.1 versions)
-- [ ] v6.0 (TiDB 6.0 versions)
 - [ ] v5.4 (TiDB 5.4 versions)
 - [ ] v5.3 (TiDB 5.3 versions)
 - [ ] v5.2 (TiDB 5.2 versions)
 - [ ] v5.1 (TiDB 5.1 versions)
 - [ ] v5.0 (TiDB 5.0 versions)
-- [ ] v4.0 (TiDB 4.0 versions)
 
 ### What is the related PR or file link(s)?