feat: replace fast-write-atomic with steno

[SgtPooki]

See https://github.com/SgtPooki/fast-write-atomic#uint8array

Task Name	ops/sec	Average Time (ns)	Margin	Samples
Uint8Array - write-file-atomic	101	9853620.467916131	±1.15%	1000
Uint8Array - fast-write-atomic	106	9421993.666924536	±1.30%	1000
Uint8Array - atomically	101	9857824.475903064	±1.16%	1000
Uint8Array - steno	2,937	340472.6759530604	±4.23%	1000
Uint8Array - steno (cached writers)	3,037	329200.16099512577	±6.35%	1000
Uint8Array - @sgtpooki/steno-patched	2,940	340053.3969886601	±9.02%	1000
Uint8Array - @sgtpooki/steno-patched (cached writers)	2,566	389624.0490563214	±8.57%	1000

### Tasks
- [x] update steno to support more than strings (it should support everything fsPromises.writeFile supports) - see https://github.com/SgtPooki/steno
- [x] replace https://github.com/ipfs/js-stores/blob/7dad9a43fdec367895467752a6fee3ac7f912ca4/packages/blockstore-fs/src/index.ts#L22
- [x] replace https://github.com/ipfs/js-stores/blob/7dad9a43fdec367895467752a6fee3ac7f912ca4/packages/datastore-fs/src/index.ts#L22

related: ipfs/helia#346 (comment)

[achingbrain]

Fixed by #285

[achingbrain]

Ah, no, #285 merged the steno impl into the PR with the tests