Fix the ignore annotations for gosec
Fix the ignore annotations for gosec

Running gosec yielded two G403 high sev problems in `pkg/pullrequest/scm.go`.
This commit replaces the ignore annotation for gosec to the most current
annotation as presented [here](https://github.com/securego/gosec#annotating-code).

Signed-off-by: Baran Dalgic <cdfafd61eea04d415fac3fe7505a0e7a489746b1@posteo.net>

tektoncd/pipeline,tektoncd/pipeline