[bug] Fix issue causing ReconstructableJobs containing certain types of metadata to error

[OwenKephart]

Summary & Motivation

Resolves: #21815

Note that while the test involved here is referencing CacheableAssetsDefinition, this same error would occur with regular assets. Any asset using a MetadataValue which contains within it a mutable object (which would be table schema and table column lineage which contain lists I believe) would encounter a similar error.

After switching the core MetadataValue class from a NamedTuple to a pydantic model, the code we use to generate hashes for our serializable objects stopped handling them. This PR fixes this.

How I Tested These Changes

After updating the test to include metadata of this type, observed the mentioned error. These changes resolved it.

[sryza]

Thanks for fixing. This NamedTuple -> DagsterModel change is the gift that keeps on giving.