Docs: Dead links to sample source directories

[martinjaeger]

Links to sample source files point to docs.zephyrproject.org instead of github.com.

Example: https://docs.zephyrproject.org/latest/samples/net/gsm_modem/README.html

Link behind samples/net/gsm_modem points to:

https://docs.zephyrproject.org/blob/master/samples/net/gsm_modem

instead of:

https://github.com/zephyrproject-rtos/zephyr/blob/master/samples/net/gsm_modem

[nashif]

@utzig you recently made a change here (#28245), can you please take a look?

[utzig]

This seems to happen after the update to west==0.8.0; previously WestManifest.from_file().get_projects(['zephyr'])[0].url was None, now with 0.8.0 it is not anymore, so I'll check what changed there. Any tips @mbolivar-nordic?

[mbolivar-nordic]

Any tips @mbolivar-nordic?

Looks like you figured it out from the API changes documentation?