- Move Interrupt and InterruptExecutor from `embassy` to `embassy-cortex-m`.
- Move Unborrow from `embassy` to `embassy-hal-common` (nothing in `embassy` requires it anymore)
- Move PeripheralMutex from `embassy-hal-common` to `embassy-cortex-m`.
Moving `new_*` to the version-specific mod allows doing the correct
register writes right there in `new`, without needing abstractions
like `enable_all`/`disable_all`.
- Scary pointer math is now contained in the tasks and events
- ppi now sets the tasks and events immediately and the struct is now zero-sized
- StaticToOne is renamed to ZeroToOne
- Used DPPI tasks and events now panic when enabled twice
