Include autodep8-* in `debcraft test` runs

As a follow-up on #7 (closed), the debcraft test command isn't complete unless it also runs the autodep8 tests for packages that don't have any autopktests defined.

For example debcraft test on setuptools does not currently run anything:

± ls -la debian/test*
ls: cannot access 'debian/test*': No such file or directory

± debcraft test
...
autopkgtest [01:41:46]: @@@@@@@@@@@@@@@@@@@@ built-tree .
autopkgtest [01:41:46]: testing package setuptools version 72.2.0-1
*                    SKIP no tests in this package
autopkgtest [01:41:46]: @@@@@@@@@@@@@@@@@@@@ summary
*                    SKIP no tests in this package

However, when it runs on e.g. Salsa CI the autodep8 steps in:

autopkgtest [00:45:48]: starting date and time: 2024-08-21 00:45:48+0000
autopkgtest [00:45:48]: version 5.39
autopkgtest [00:45:48]: host runner-f0fdd533-project-93572-concurrent-0; command line: /usr/bin/autopkgtest --no-built-binaries '--setup-commands=echo '"'"'/builds/python-team/packages/setuptools/debian/output/setuptools_72.2.0-1+salsaci+20240821+1_amd64.changes unstable/amd64'"'"' > /var/tmp/debci.pkg 2>&1 || true' '--setup-commands=echo '"'"'Acquire::Retries "10";'"'"' > /etc/apt/apt.conf.d/75retry 2>&1 || true' --user debci --apt-upgrade --output-dir=/builds/python-team/packages/setuptools/debian/output/debci /builds/python-team/packages/setuptools/debian/output/setuptools_72.2.0-1+salsaci+20240821+1_amd64.changes -- lxc --sudo --name ci-234-c6488e0e autopkgtest-unstable-amd64
autopkgtest [00:45:54]: testbed dpkg architecture: amd64
autopkgtest [00:45:54]: testbed apt version: 2.9.8
autopkgtest [00:45:54]: @@@@@@@@@@@@@@@@@@@@ test bed setup
...
autopkgtest [00:46:12]: test autodep8-python3: set -e ; for py in $(py3versions -r 2>/dev/null) ; do cd "$AUTOPKGTEST_TMP" ; echo "Testing with $py:" ; $py -c "import pkg_resources; print(pkg_resources)" ; done
autopkgtest [00:46:12]: test autodep8-python3: [-----------------------
Testing with python3.12:
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 95, in <module>
    import packaging.specifiers
ModuleNotFoundError: No module named 'packaging'
autopkgtest [00:46:12]: test autodep8-python3: -----------------------]
autopkgtest [00:46:12]: test autodep8-python3:  - - - - - - - - - - results - - - - - - - - - -
autodep8-python3     FAIL non-zero exit status 1
autopkgtest [00:46:12]: @@@@@@@@@@@@@@@@@@@@ summary
autodep8-python3     FAIL non-zero exit status 1