[set_fifo_depths] Adding a new transformation to split fifos larger than the max allowed depth

[Hotfix] Update setup-python in pre-commit gha

[Hotfix] Add missing Jenkins marker in fifosizing test

[CustomOp] Fix setting of NumReps in Thresholding and N in Eltwise node

[Hotfix] Update minimize accumulator width for bipolar case

Fixes for automatically generated documentation

Predecessor handling refactor and identity fallback

Hotfix: Updating code to use correct numpy types

Hotfix: delete numpy.str in datapacking

Update requirements

Update GHA to use Ubuntu 20.04

Pure C++ Verilator-based FIFO sizing