SLSA v1 should be wrapped into intoto v1 statement

[chuangw6]

Expected Behavior

SLSA v1 predicate should be wrapped into intoto v1 statement

Actual Behavior

It's wrapped into intoto v0.1 statement

chains/pkg/chains/formats/slsa/v2alpha2/internal/pipelinerun/pipelinerun.go

Line 47 in 70c8c7d

Type: intoto.StatementInTotoV01,

Related

in-toto/in-toto-golang#265

It would be ideal if intoto defines the v1.0 statement type in intoto project and chains uses it for _type field.

[chuangw6]

cc @chitrangpatel @wlynch @lcarva