fix: Rename Seeed XIAO bootloader files to right version 0.6.2

The version of bootloader in platform.txt is not equal to the bootloader files version for the Seeed XIAO BLE boards. There is an error in Arduino console while trying to burn the bootloader:
```
Error: Invalid value for '-pkg' / '--package': File 'C:\\Users\\Morgan\\AppData\\Local\\Arduino15\\packages\\Seeeduino\\hardware\\nrf52\\1.0.0/bootloader/Seeed_XIAO_nRF52840/Seeed_XIAO_nRF52840_bootloader-0.6.2_s140_7.3.0.zip' does not exist.
Failed to burn bootloader: uploading error: exit status 2
```

Author: SenMorgan