Constant META_DEPENDS_ON 

pub const META_DEPENDS_ON: &str = "depends_on";

Step-level metadata: comma-joined list of upstream stage / job names this step’s container declared via a non-default dependsOn: value. Default ADO behaviour (“depends on the previous job/stage”) is NOT stamped — only explicit overrides. Currently a parser-side hook for future cross-job taint rules; no consumer rule exists yet.