[CheckpointWrapper] Use correct extension during atomic writing

4 jobs for atomic-writing in 16 minutes and 16 seconds (queued for 1 second)
Status Name Job ID Coverage
  Build
passed build_linux_37 #240768
docker

00:12:39

passed build_linux_38 #240769
docker

00:11:23

passed build_macos_intel_37 #240766
macos intel

00:16:16

passed build_macos_intel_38 #240767
macos intel

00:13:46