go: Update module github.com/jackc/pgx/v5 to v5.5.5 [16.10]
Cherry-pick !6754 (merged) into 16-10-stable to fix the failing vulnerability job (https://gitlab.com/gitlab-org/gitaly/-/jobs/6469117670).
Edited by Reuben Pereira
Cherry-pick !6754 (merged) into 16-10-stable to fix the failing vulnerability job (https://gitlab.com/gitlab-org/gitaly/-/jobs/6469117670).