Deploy test workflow cannot be run from a feature branch

[mslw]

The deploy test workflow can be triggered manually, and a branch can be chosen. However, when I tried to run from locale branch, I got:

Run cd sfb1451_data_entry
+ destination_root=www
+ local_part=z03-db
+ create_switch_page=
+ '[' Xz03-db '!=' X ']'
+ destination_dir=www/z03-db
+ create_switch_page=1
+ suffix=
+ dont_push=
+ '[' 1 -gt 0 ']'
+ '[' test == test ']'
+ suffix=-test
+ '[' test == --dont-push ']'
+ shift
+ '[' 0 -gt 0 ']'
+ git checkout deploy
Switched to a new branch 'deploy'
branch 'deploy' set up to track 'origin/deploy'.
+ git pull
Already up to date.
+ master_version_file=master-version-test
+ touch master-version-test
++ git rev-parse master
fatal: ambiguous argument 'master': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
+ new_master=master

https://github.com/psychoinformatics-de/sfb1451_data_entry/actions/runs/8194423195

[mslw]

As a side note, the test workflow modifies the index-test file, while all the rest (incl. updating the wsgi script) is shared between test and non-test. Hence, it is mainly for testing the workings of the html+js form.