CI: install Git on Fedora 41
This makes diagnosing failures slightly simpler.
It was discovered that this environment does not have Git available, causing the Graphviz version to be incorrectly derived in intermediate (development) versions:
++ python3 gen_version.py
Warning: build not started in a Git clone, or Git is not installed: setting
version date to 0.
+ GV_VERSION=13.0.0~dev.0`
Gitlab: #2672 (closed)
This was discovered while working on some #2656 (closed) related changes.