Implement no_reset mode

[makermelissa]

Description

The no_reset option is very useful for for doing passthrough updates as the reset functionality causes the passed-through board to not respond. I added the no_reset feature in the simplest way possible (just not calling reset()), though in future updates, feel free to change it.

Related

Fixes #178. Also, a partial fix for adafruit/Adafruit_WebSerial_ESPTool#321.

Testing

I tested this using a local version of https://github.com/adafruit/Adafruit_WebSerial_ESPTool. With this fix alone, it fails on the first attempt and then works on subsequent attempts. I will have another PR for that repo (related to our passthrough code) which makes it work consistently.

For hardware, I am using a Feather M4 and following the instructions in https://learn.adafruit.com/upgrading-esp32-firmware/upgrade-external-esp32-airlift-firmware-2.

---

Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes.
• All CI checks (GH Actions) pass.
• Documentation is updated as needed.
• Tests are updated or added as necessary.
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.

[brianignacio5]

Thanks @makermelissa ! I do think that rebasing #146 will provide a much comprehensive reset mode experience though.

Update: I just rebase #146 with latest changes. Could you take a look ?

[makermelissa]

Yes, I'll test it out.

[makermelissa]

Closing in favor of #146.