Fix connecting to S2 over USB

[bugadani]

Closes #656

cargo run --bin espflash board-info                                                                       
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.64s
     Running `target\debug\espflash.exe board-info`
[2025-03-24T14:50:24Z INFO ] Serial port: 'COM57'
[2025-03-24T14:50:24Z INFO ] Connecting...
[2025-03-24T14:50:24Z INFO ] Using flash stub
Chip type:         esp32s2 (revision v1.0)
Crystal frequency: 40 MHz
Flash size:        8MB
Features:          WiFi, No Embedded Flash, Embedded PSRAM 2MB, ADC and temperature sensor calibration in BLK2 of efuse V2
MAC address:       70:04:1d:fa:00:c4

Security Information:
=====================
Flags: 0x00000000 (0)
Key Purposes: [0, 0, 0, 0, 0, 0, 0]
Secure Boot: Disabled
Flash Encryption: Disabled
SPI Boot Crypt Count (SPI_BOOT_CRYPT_CNT): 0x0

[maxwen]

Tested and works

[jessebraham]

Thanks!

[aemarkov]

I've tried it, but in my case espflash can connect if only esptool is connected first. See #860 860