Make sure not to use apt in the workflows that use flatpak-platform docker images

[ryonakano]

Problem

In #234, we rebased ghcr.io/elementary/flatpak-platform/runtime docker image on Flathub action image that doesn't ship with apt, so the Install git, python3-git and jq step:

  gettext:
    name: Gettext
    runs-on: ubuntu-latest
    container:
      image: ghcr.io/elementary/flatpak-platform/runtime:8.2-x86_64
      options: --privileged

    steps:
    - name: Install git, python3-git and jq
      run: |
        apt-get update        # this will fail!
        apt-get install git jq python3-git -y

will fail: https://github.com/elementary/calculator/actions/runs/24336768166/job/74193731827

Run apt-get update
  apt-get update
  apt-get install git jq python3-git -y
  shell: sh -e {0}
/__w/_temp/7466f102-0a3e-4bb3-ba8c-c108f682fe6d.sh: line 1: apt-get: command not found
Error: Process completed with exit code 127.

Proposal

Make sure not to use apt in the workflows that use flatpak-platform docker images.

Prior Art (Optional)

No response

[ryonakano]

The new docker image already contains git and jq, but does not GitPython:

user@elementary-daily:~/work/elementary/calculator (main =)$ docker run --rm -it ghcr.io/elementary/flatpak-platform/runtime:8.2-aarch64 bash
bash-5.3# apt
bash: apt: command not found
bash-5.3# dnf
bash: dnf: command not found
bash-5.3# which git
/usr/sbin/git
bash-5.3# which jq
/app/bin/jq
bash-5.3# python3
Python 3.13.13 (main, Nov 10 2011, 15:00:00) [GCC 15.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from git import Repo
Traceback (most recent call last):
  File "<python-input-0>", line 1, in <module>
    from git import Repo
ModuleNotFoundError: No module named 'git'
>>>

So replacing Install git, python3-git and jq step to python3 -m pip install GitPython should work.

bash-5.3# python3 -m pip install GitPython
Collecting GitPython
  Downloading gitpython-3.1.49-py3-none-any.whl.metadata (14 kB)
Collecting gitdb<5,>=4.0.1 (from GitPython)
  Downloading gitdb-4.0.12-py3-none-any.whl.metadata (1.2 kB)
Collecting smmap<6,>=3.0.1 (from gitdb<5,>=4.0.1->GitPython)
  Downloading smmap-5.0.3-py3-none-any.whl.metadata (4.6 kB)
Downloading gitpython-3.1.49-py3-none-any.whl (212 kB)
Downloading gitdb-4.0.12-py3-none-any.whl (62 kB)
Downloading smmap-5.0.3-py3-none-any.whl (24 kB)
Installing collected packages: smmap, gitdb, GitPython
Successfully installed GitPython-3.1.49 gitdb-4.0.12 smmap-5.0.3
WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager, possibly rendering your system unusable. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv. Use the --root-user-action option if you know what you are doing and want to suppress this warning.
bash-5.3# python3
Python 3.13.13 (main, Nov 10 2011, 15:00:00) [GCC 15.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from git import Repo
>>>