Fixes to some leaky buckets in astrid shared memory buffers
Cleanup to python astrid instruments, adc work

- Moved Instrument init into main thread
- Python instruments use the same astrid_instrument_tick routine as C
- Bugfixes to sequencer priority queue
Fixes to sequencer priority queue indexing, adds basic linenoise history support, and disables the ADC writes again.
Remove old shared memory buffer interfaces

Fixes to lpsampler ringbuffer read/write

First pass simple.c and sampler.c test programs

Some reworking of python interfaces, still needs work
Flailing around
Use flexible array members in libpippi buffers. More work on the new lpsampler interfaces and ADC in astrid. (WIP) Plus misc bugfixes.
Fix message sequencing in new style astrid instruments
Relay internal messages to python and try to handle everything else internally
Move cython renderer later into pippi, first pass support for new style python instruments
Remove redis!
First pass support python renderers in new astrid C instruments
Merge branch 'main' of git.sr.ht:~hecanjog/pippi
Add first pass linenoise cmd repl to astrid C instruments
Add shapeosc example, astrid key serializer, fix pulsar ugen...
First pass bufstr encoder
Remove some debugging messages
Send shutdown message if threads are still waiting on cleanup
Update some deps and tweak rain test pulsar program
Remove cirrus CI