Fix PR template (#16439)

### What problem does this PR solve?

Update Github PR template

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

.github/pull_request_template.md

@@ -1,12 +1,3 @@
-### What problem does this PR solve?
+### Summary
 
 _Briefly describe what this PR aims to solve. Include background context that will help reviewers understand the purpose of the PR._
-
-### Type of change
-
-- [ ] Bug Fix (non-breaking change which fixes an issue)
-- [ ] New Feature (non-breaking change which adds functionality)
-- [ ] Documentation Update
-- [ ] Refactoring
-- [ ] Performance Improvement
-- [ ] Other (please describe):