Fix tsc error with TextDecoderStream

[jesserockz]

Error: src/logs-webserial/ewt-console.ts(96,32): error TS2345: Argument of type 'TextDecoderStream' is not assignable to parameter of type 'ReadableWritablePair<string, Uint8Array<ArrayBufferLike>>'.
  Types of property 'writable' are incompatible.
    Type 'WritableStream<BufferSource>' is not assignable to type 'WritableStream<Uint8Array<ArrayBufferLike>>'.
      Type 'BufferSource' is not assignable to type 'Uint8Array<ArrayBufferLike>'.
        Type 'ArrayBuffer' is missing the following properties from type 'Uint8Array<ArrayBufferLike>': BYTES_PER_ELEMENT, buffer, byteOffset, copyWithin, and 24 more.
Error: Process completed with exit code 2.