mpremote rm -r : behavior in the presence of ROMFS

Description

I have gotten used to mpremote rm -rv : to clear out the filesystem for those boards that do not have an "erase flash" option in the firmware loader.

Recently that has become a stumbling block when device have ROMFS
mpremote then raises : mpremote: rm: ./rom: No such file or directory.
Which is a terminating error - and stops the recursive removal,
and requires subsequent one-by-one removal of the remain files and folders.

(micropython) jos@SB26:~/micropython/tools/mpremote/tests$ mpremote rm -rf :
rm :
mpremote: rm: ./rom: No such file or directory.
(micropython) jos@SB26:~/micropython/tools/mpremote/tests$ mpremote tree
tree :
:/
├── file1.txt
├── file3.txt
├── lib
│   ├── __future__.mpy
│   ├── __future__.py
│   ├── boardname.py
│   ├── createstubs.mpy
│   ├── createstubs.py
│   ├── createstubs_db.mpy
│   ├── createstubs_db.py
│   ├── createstubs_mem.mpy
│   ├── createstubs_mem.py
│   └── modulelist.txt
├── modulelist_exclude.txt
├── petstore.py
├── rom
│   ├── bar.mpy
│   ├── foo.mpy
│   └── vector-text.svg
└── udp_client.py

I think the best way to handle this is for mpremote to:

• treat this error on a /romxx folder as a non-blocking error , but log it as an error
• stop traversing that folder
• continue the rest of the rm -r

Code Size

no FW size impact

Implementation

I intend to implement this feature and would submit a Pull Request if desirable

Code of Conduct

Yes, I agree

Start by locating mpremote's recursive rm handling and reproduce mpremote rm -rf : with a device containing a ROMFS directory. Verify that the ROMFS traversal error is logged, that traversal of that directory stops, and that removal continues for the remaining filesystem entries.