"Erase before flash" failing when flashing backpack on Radiomaster TX16s via EdgeTx passthrough

## Expected Behavior

should have erased the chip before flashing it

## Current Behavior

displays an error:
```
usage: flasher.pyz [-h] [--dir DIR] [--phrase PHRASE] [--ssid SSID] [--password PASSWORD] [--auto-wifi AUTO_WIFI] [--no-auto-wifi] [--target TARGET] [--flash {uart,passthru,etx,wifi,dir}] [--out OUT] [--port PORT] [--baud BAUD] [--force] [--confirm] [file] flasher.pyz: error: unrecognized arguments: --erase
```

## Steps to Reproduce

1. connect Tx16s over usb in VCP mode

2. open ExpressLRS configurator Backpack tab

3. select "RadioMaster TX16S Internal 2.4GHz TX"

4. select flashing method "EdgeTX Passthrough"
5. tick "Erase before flash"
6. flash. -> error appears

## Context

i am having a problem that the backpack does not expose a wifi despite being "on" and "telemetry" set to "wifi". All manuals i've seen suggest that it should appear by itself, i should not use "Enable Backpack Wifi" in the lua script. Yet it does not. So i thought, erasing configuration memory might help. So far, i have not found a working way to erase it.
## Your Environment

- ELRS configurator v1.7.11
- Operating System and version: Windows 10
- TX hardware: Radiomaster TX16s MK2
- RX hardware: BetaFPV ELRS nano Rx
- flight controller: PX4 on Pixhawk 6c