Enforce strict-YAML mode for lima.yaml

[jandubois]

Don't allow duplicate fields, or fields not defined in our schema.

Rancher Desktop hasn't used non-strict YAML in over 2 years; this has been fixed in rancher-sandbox/rancher-desktop#2898

Users have the option of storing custom data in params now (and could have used obscure env names even before).

[AkihiroSuda]

Thanks, but this might be considered as a breaking change

[jandubois]

Thanks, but this might be considered as a breaking change

It is, but it has been deprecated for over 2 years now (since 0.12.0), and issuing a warning for over 2 years: #1045.

So yes, it should be mentioned in the release notes. But if we never want to remove it, then we should maybe get rid of the deprecation warning and just print the non-strict YAML errors.

[afbjorklund]

For me it is quite normal to get warnings, when switching between alternative futures and the release version.

WARN[0000] Non-strict YAML is deprecated and will be unsupported in a future version of Lima  comment="main file \"/home/anders/.lima/raspberrypi/lima.yaml\"" error="[14:3] unknown field \"address\"\n  11 |   writable: true\n  12 | \n  13 | ssh:\n> 14 |   address: raspberrypi.local\n         ^\n  16 | provision:\n  17 | - mode: system\n  18 |   "
WARN[0000] Unknown driver: ext                          
WARN[0000] instance "raspberrypi" has errors             errors="[field `vmType` must be \"qemu\", \"vz\", \"wsl2\"; got \"ext\"]"

If these are changed from warnings to errors, I would need to use a separate LIMA_HOME for experimenting...

Which is "OK", I suppose. Can't say that it hasn't warned :-)

... will be unsupported in a future version ...