Problem

Tiered storage is being removed. Evergreen still defines and schedules tasks that only exist to run the Python tiered hook, dir_store delay injection, bench-tiered-push-pull, and checkpoint-stress with -PT.

Change

Delete these tasks and their build-variant references: unit-test-hook-tiered, unit-test-hook-tiered-with-delays, unit-test-hook-tiered-timestamp, unit-test-hook-tiered-timestamp-quick, bench-tiered-push-pull, checkpoint-stress-test-tiered, precise-checkpoint-stress-test-tiered. Drop code-coverage entries for test_tiered04 / test_tiered08. Keep non-tiered checkpoint-stress-test / precise-checkpoint-stress-test (tiered: 0). Do not change src/.

Test

Confirm remaining Evergreen YAML still parses. No engine behavior change.