pipeline: fix installation of package in "container-image" job (see below)

```
#12 [build 8/9] RUN pipenv install --deploy     && pipenv run location-guessing-game-telegram-bot --help     && pipenv graph     && pipenv run pip freeze     && rm -rf .git/ /tmp/pipenv-cache     && chmod -cR a+rX .
#12 1.174 Installing dependencies from Pipfile.lock (7005a3)...
#12 13.85 ERROR:setuptools_scm.file_finder_git:listing git files failed - pretending there aren't any
#12 27.28 An error occurred while installing -e .! Will try again.
#12 33.65 An error occurred while installing -e .! Will try again.
#12 33.65 Installing initially failed dependencies...
#12 40.34 Error: the command location-guessing-game-telegram-bot could not be found within PATH or Pipfile's [scripts].
#12 ERROR: process "/bin/sh -c pipenv install --deploy     && pipenv run location-guessing-game-telegram-bot --help     && pipenv graph     && pipenv run pip freeze     && rm -rf .git/ $PIPENV_CACHE_DIR     && chmod -cR a+rX ." did not complete successfully: exit code: 1
```
https://web.archive.org/web/20220925043619/https://github.com/fphammerle/location-guessing-game-telegram-bot/actions/runs/3117399045/jobs/5061813954
https://web.archive.org/web/20220925043709/https://pipelines.actions.githubusercontent.com/serviceHosts/bf0ed7da-3784-4b0a-ba8c-993e6babb599/_apis/pipelines/1/runs/855/signedlogcontent/2?urlExpires=2022-09-25T04%3A37%3A40.3352741Z&urlSigningMethod=HMACV1&urlSignature=IxgFQ7FGRiXOtEWuTk1StKN%2BpijVqhCN8aNBQOrioCM%3D

.github/workflows/container-image.yml

@@ -17,14 +17,15 @@ jobs:
     # > By default, this action uses the Git context so you don't need to use
     # > the actions/checkout action to checkout the repository because this
     # > will be done directly by buildkit. [...]
-    # > any file mutation in the steps that precede [...] will be ignored
+    # > any file mutation in the steps that precede [...] will be ignored,
+    # > including processing of the .dockerignore file
     # https://github.com/marketplace/actions/build-and-push-docker-images
     # > The commit history is not preserved.
     # https://docs.docker.com/engine/reference/commandline/build/#git-repositories
     - uses: docker/build-push-action@v3.1.0
       with:
-        build-args: |
-          SETUPTOOLS_SCM_PRETEND_VERSION=0 # git history unavailable (see above)
+        build-args: | # git history unavailable (see above)
+          SETUPTOOLS_SCM_PRETEND_VERSION=0
         platforms: |
           linux/amd64
         # missing cffi wheel for linux/arm/v7