2.3.0

• 🔥 Switched from Apache 2 to GPL 3 license (which was effectively the case ever since Calamari 2.0)
• 🔥 Update to ocrd-fork-tfaip==1.2.7 (supporting Tensorflow up to and including 2.15)
• Adapt to changes in Numpy, Pillow, Python 3.9 and 3.11
• 🔥 Switch to Tensorflow SavedModel format as backend for models (because they are compatible across Python versions)
  new checkpoint format version identifier is 6, updates will happen automatically (as usual), if possible
  to migrate older models, you might need to go back to Python 3.8 once
• Implement --non_existing_pred_handling_mode evaluator param (providing new skip and error, in addition to current and now default empty)
  (fixes missing --non_existing_file_handling_mode from Calamari 1)
• Fix warmstarting: keep network architecture
• Introduce new model parameter temperature (inactive by default, can be applied ex post)
  for pre-scaling the logits, controlling steepness of probability distribution prior to CTC)
• Respect directory of PageXML datasets: output as input, unless --output-dir is given
• Change label PERCENT to PERCENT_CER in evaluator's confusion table
• Fully git-controlled versioning (via setuptools_scm)