Migrates to serde-saphyr

[mnmaita]

Objective

• Migrate from serde_yml to serde-saphyr.
• Related to Update serde_yml requirement from 0.0.12 to 0.0.13 #26074.

Solution

• Migrated to serde-sephyr using only the necessary features of the crate and by migrating code that was previously using serde_yml.

Testing

• I will need some directions to properly test this changeset, but I think the changes are pretty straightforward. I could take a stab at adding a test or two if it's deemed worthwile.