Nightlies are failing due to kconfig mismatch.
It would seem this is a result of bringing in the USB stuff.
I assume that this uses ztimer periph_timer as a backend as periph_timer is already selected.
However, kconfig only resolves one and not recursively making it hard to match.
For not a hack is added to override for these boards.
- Created new `bluepill-128kib` as 128KiB version of the `bluepill`
- Created new `blackpill-128kib` as 128KiB version of the `blackpill`
- Updated `openocd.cfg` to allow flashing 128KiB of ROM