Windows installer does not set environment for first run

The windows installer invites you to start a bash shell at the end of
the install process. I configured git to use plink as my ssh tool.
This requires the GIT_SSH variable to be set. It is not set in this
first run, so git doesn't work properly. The installer was
Git-2.24.0.2-64-bit.exe

$ grep plink first-run-env second-run-env
second-run-env:GIT_SSH=C:\Program Files\PuTTY\plink.exe
second-run-env:SVN_SSH=C:\Program Files\PuTTY\plink.exe