devel/git: Fix build using SETENVI and WRK_ENV

Followup needed changes after 572f23616926 and call upstream build
scripts properly

PR: 279527
Reported by: O. Hartmann <ohartmann@walstatt.org>
MFH: 2024Q2
Sponsored by: Rubicon Communications, LLC ("Netgate")

(cherry picked from commit bc5cba2753c702214cfd9b7ed51385f6f2b8428f)