rez-build: use new features of rez_release modes to avoid using rez's vcs shell scripts.  these scripts are now deprecated.
rez-build: use new features of rez_release modes to avoid using rez's vcs shell scripts.  these scripts are now deprecated.

instinct-vfx/rez,instinct-vfx/rez,nerdvegas/rez,nerdvegas/rez