change breaking change check list in PR (#12871)
change breaking change check list in PR (#12871)

* change breaking change check list in PR

Update API in preview version over 1 year is not valid now.

* Update PULL_REQUEST_TEMPLATE.md

* Update PULL_REQUEST_TEMPLATE.md
AsrOneSdk/azure-rest-api-specs,naveedaz/azure-rest-api-specs,yugangw-msft/azure-rest-api-specs,brjohnstmsft/azure-rest-api-specs,yugangw-msft/azure-rest-api-specs,solankisamir/azure-rest-api-specs,AuxMon/azure-rest-api-specs,johanste/azure-rest-api-specs,AppPlatPerf/azure-rest-api-specs,AuxMon/azure-rest-api-specs,vladrai/azure-rest-api-specs,solankisamir/azure-rest-api-specs,brjohnstmsft/azure-rest-api-specs,AppPlatPerf/azure-rest-api-specs,johanste/azure-rest-api-specs,naveedaz/azure-rest-api-specs,vladrai/azure-rest-api-specs,AsrOneSdk/azure-rest-api-specs