a package that requires `forge` cannot be compiled without git available

[jian-lin]

similar to magit/magit#5490

to reproduce, compile gptel-forge-prs-20251216.923 without git available, you will see:

Error: file-missing ("Searching for program" "No such file or directory" "git")
  call-process("git" nil t nil "version")
  process-file("git" nil t nil "version")
  magit-process-file("git" nil t nil "version")
  magit-process-git(t "version")
  magit-git-version()
  forge-startup-asserts()
  byte-code("\10\203\n\0\301 \210\202\20\0\302\303\301\304#\210\301\207" [after-init-time forge-startup-asserts add-hook after-init-hook t] 4)
  require(forge)
  byte-compile-file-form-require((require 'forge))
  byte-compile-file-form((require 'forge))
  byte-compile-file("/nix/store/3cb5zjlf0zsii637c2ypi4q0k93kz4s0-emacs-gptel-forge-prs-20251216.923/share/emacs/site-lisp/elpa/gptel-forge-prs-20251216.923/gptel-forge-prs.el")

• magit-20251217.1836
• forge-20251201.1658

[tarsius]

I can confirm. Turns out magit-git-version is too messed up to address this in ten minutes, so this will have to wait until next year.