Cashing broken in Kkrimp workflow tests

[PhilippRue]

The caching functionality that is required for workflow tests seems to be broken. For example in the ci actions to commit 8cc2191 the kkrimp_sub_wc workflow tests fail although the test files have been recreated and the test works when the impurity code is executed locally.

A second run however then does not use the caching file but reruns the executables. Thus caching does not work and the workflow tests cannot run at the moment.

[PhilippRue]

To fix this caching needs to be reenabled in the following tests

• workflows/test_kkrimp_sub_wc.py
• workflows/test_kkrimp_dos_wc.py
• workflows/test_kkrimp_full_wc.py
• workflows/test_combine_imps.py