Bug with create MergeRequest action on a non default branch pipeline

Resolve with MergeRequest action for a security finding on a non-default branch is creating vulnerability with present_on_default_branch as true.

Related discussion !128372 (comment 1506185467)

the current behaviour is when we create a merge request from vulnerability finding on a non default branch pipeline, find or create a vulnerability from security finding is setting present_on_default_branch = true which satisfies the trigger condition and so the vulnerability_reads record are also getting created.