Updating to a newer version of serde_yaml
In Debian, there is a need to update serde-yaml as it seems to be required for other packages.
However, this breaks squeekboard due to a change in the way this crate handles enums: it now requires using YAML tags in order to identify which enum variant to use, at least for "complex" variants (structs/variants with parameters). In squeekboard, this affects the "locking" and "set_view" button actions.
This can be fixed by applying this patch, but that would introduce a Debian-only difference regarding how layout files are written and validated (also note, the patch is incompatible with serde-yaml v0.8). This change would also affect users relying on custom layout files.
My opinion is that importing the aforementioned patch and bumping the serde-yaml dependency would be desirable, but I'd rather do this in a coordinated way, say for a new squeekboard release (with a specific mention of this change in the release notes, so affected users know how to fix their layout files), but I'm open to further discussing this matter.