Revert "Add PULL_REQUEST_TEMPLATE (#24454)" (#24486)

This reverts commit 47e4e643.

.github/PULL_REQUEST_TEMPLATE.md

-####Required（必填, multiple choices, two at most）
-- PR type（PR 类型） is ( ):
-A. New features（新功能）--------------- D. Performance optimization（性能优化）
-B. Bug fixes（问题修复）------------------ E. Breaking changes（向后不兼容的改变）
-C. Function optimization（功能优化）-- F.  Others（其它）
-
-- PR changes（改动点）is ( ):
-A. OPs（operators）------------------------ C. Docs（文档）
-B. APIs（接口）------------------------------D. Others（其它）
-
-- Use one sentence to describe what this PR does.（简述本次PR的目的和改动）
-
-#### Optional（选填）
-
-- Describe what this PR does in detail. If this PR fixes an issue, please give the issue id.
-  <!-- DESCRIBE THE BUG OR REQUIREMENT HERE. eg. #2020（格式为 #Issue编号）-->
-- If you modified docs, please make sure that both Chinese and English docs were modified and provide a preview screenshot. （文档必填）
-   <!-- ADD SCREENSHOT HERE IF APPLICABLE. -->
-- Please write down other information you want to tell reviewers.