feather_stm32f405_express not running blinky uf2

### Operating System

Windows 10

### INFO_UF2.TXT

```
TinyUF2 Bootloader 0.9.4 - st/cmsis_device_f4 (v2.6.4-1-g2615e86) st/stm32f4xx_hal_driver (v1.7.9) tinyusb (0.12.0-203-ga4cfd1c69)
Model: Adafruit Feather STM32F405 Express
Board-ID: STM32F405-Feather-revB
Date: May 30 2022
```

### What happened ?

TinyUF2 doesnt seem to be running programs copied over to the MSC.

### How to reproduce ?

1. Compile blink example for feather_stm32f405_express
2. Convert bin to uf2 `uf2conv -c -b 0x08010000 -f 0x57755a57 -o...`
3. Copy uf2 to MSC device
4. Board resets back into tinyuf2 bootloader (neopixel is green + MSC device mounts)

### Debug Log

_No response_

### Screenshots

Bootloader is there

Blink program seems to start at 0x08010000

Start by reproducing the feather_stm32f405_express blink build and the shown uf2conv command, then inspect how the copied UF2 is handled at 0x08010000. Compare the bootloader reset behavior with the reported INFO_UF2.TXT and screenshots. Done means a converted blink UF2 copied to the MSC device launches the program instead of returning to TinyUF2.

Written by the indexing model from the issue text.