Fix server-test CI job testing against the PyPI SDK #662

Currently, the server-test job in .github/workflows/pr.yml does not test the server against the local SDK, but against the latest SDK release from PyPI. This is the same problem that #593 fixed for the compliance tool jobs and #611 for server-static-analysis: the job checks out the repository shallow, so setuptools_scm builds the local SDK as 0.1.dev1+g<sha>, which does not satisfy the basyx-python-sdk>=1.0.0 constraint of the server. Thus, pip install .[dev] replaces the local SDK with the PyPI release. The server-test job was only introduced afterwards in #627, without the workaround.

This makes develop fail as soon as the server depends on an SDK change that is not released yet. This happened for the first time with #620: the server passes the new attribute argument to the SDKs check(), which the PyPI release 2.2.0 does not accept, resulting in 124 errors (see the failed run).

The server-test job should check out with fetch-depth: 0 as well, like the other jobs with a TODO(#592). The proper solution is tracked in #592.