scripts/requirements: update PyYAML to >=5.1

[pabigot]

sanitycheck now requires yaml.FullLoader to support generating
hardware maps. This feature was introduced in PyYAML 5.1.

Signed-off-by: Peter Bigot [email protected]

[ulfalizer]

Wonder if #20210 might make this moot and be compatible with both old and new PyYAML versions.

Looks like yaml.load(..., loader=yaml.Loader) works the same as yaml.load(..., loader=yaml.UnsafeLoader) with PyYAML >= 5.1, from digging through the code a bit.

IIRC there was some reason to not update PyYAML earlier, but can't remember what it was, and I'm not sure if there's still a reason. extract_dts_includes.py has a workaround that edtlib.py inherited (search for "add_constructor" in the code).

yaml/pyyaml#265 has some information too.

[ulfalizer]

Adding @mike-scott. He added commit 4278bf5 ("scripts/dts: Fix for PyYAML 5.1 Loader changes") back in March.

[ulfalizer]

Guessing it might just've been because it was so new back then. Fine with me in that case at least.

[mike-scott]

LGTM