fix: Fix breadcrumb timestamp casting and its tests #3905

Job	Run time
Data Processing (latest) (3.6, ubuntu-20.04)	1m 17s
Data Processing (latest) (3.7, ubuntu-20.04)	2m 3s
Data Processing (pinned) (3.6, ubuntu-20.04)	3m 5s
Data Processing (latest) (3.8, ubuntu-20.04)	3m 56s
Data Processing (pinned) (3.7, ubuntu-20.04)	3m 54s
Data Processing (latest) (3.10, ubuntu-20.04)	2m 52s
Data Processing (pinned) (3.8, ubuntu-20.04)	3m 50s
Data Processing (latest) (3.11, ubuntu-20.04)	4m 32s
Data Processing (pinned) (3.9, ubuntu-20.04)	1m 54s
Data Processing (latest) (3.12, ubuntu-20.04)	4m 36s
Data Processing (pinned) (3.10, ubuntu-20.04)	4m 18s
Data Processing (pinned) (3.11, ubuntu-20.04)	4m 42s
Data Processing (pinned) (3.12, ubuntu-20.04)	3m 33s
All Data Processing tests passed	1s
	44m 33s

Provide feedback