fix: host vertex remember last channel number send to audio thread

[mdydek]

Closes #1332

⚠️ Breaking changes ⚠️

Introduced changes

• previously the decision whether to change the channel count was decided on the host thread, but queried using value from render thread, on which already scheduled changes could not yet take place, right now, remember the last value that was sent to the render thread and if that differs schedule buffer swap
• refactor channel number computation, right now it does not traverse through inputs, because it do not have to, only current node and outputs further in the graph could change

Checklist

• Linked relevant issue
• Updated relevant documentation
• Added/Conducted relevant tests
• Performed self-review of the code
• Updated Web Audio API coverage
• Added support for web
• Updated old arch android spec file

[github-actions]

WPT non-regression comparison

PASS — no regressions · 0 improved section(s) · overall 3427 → 3427 (0)

Unchanged sections (28)

Spec section	Base pass	Head pass	Delta
Processing model	1	1	0
Other	56	56	0
AnalyserNode	138	138	0
AudioBuffer	140	140	0
AudioBufferSourceNode	220	220	0
AudioContext	58	58	0
AudioNode	261	261	0
AudioParam	680	680	0
BiquadFilterNode	275	275	0
ChannelMergerNode	30	30	0
ChannelSplitterNode	7	7	0
ConstantSourceNode	64	64	0
ConvolverNode	178	178	0
DelayNode	127	127	0
DestinationNode	0	0	0
DynamicsCompressorNode	4	4	0
GainNode	15	15	0
IIRFilterNode	87	87	0
MediaElementAudioSourceNode	0	0	0
MediaStreamAudioDestinationNode	1	1	0
MediaStreamAudioSourceNode	0	0	0
OfflineAudioContext	35	35	0
OscillatorNode	104	104	0
PannerNode	727	727	0
PeriodicWave	33	33	0
ScriptProcessorNode	0	0	0
StereoPannerNode	104	104	0
WaveShaperNode	82	82	0

_{Baseline: eb17d846e2e16cf3c82e0807a35f30565f10653e · Candidate: ad1dcc4d097b62f64b3db35e943ee1c2193507e9}

_{Workflow run · this comment is updated on every push.}