CI builds always "fail"

[lmoureaux]

Describe the bug

Since the transition to AutoRevision, every single CI build in my private repo generates a failure message because git is found and it fails to find the correct revision (there is no tag in my repo).

To Reproduce

Steps to reproduce the behavior:

1. Go to https://github.com/lmoureaux/freeciv21/runs/5080979854?check_suite_focus=true

Expected behavior
The build doesn't rely on the presence of a tag in the repo.

Screenshots

-- Found Git: /usr/bin/git (found version "2.35.1") 
-- git was found and we are in a valid repository. Using git commands.
-- Git HEAD Commit Hash: (hex) ff401 and (dec) 1045505
-- Last tag commit hash: 
fatal: No names found, cannot describe anything.
-- Latest Git Tag: 
CMake Error at CMakeLists.txt:47 (project):
  VERSION "NOTFOUND.NOTFOUND.1045505" format invalid.


-- Configuring incomplete, errors occurred!