Fix TAE context inference

[charlespwd]

What are you adding in this PR?

*.extension.toml & snippets/ = TAE, it doesn't have to be strictly shopify.extension.toml. Newer templates don't use the old name.

What did you learn?

• Your shopify extension file doesn't need to be called shopify.extension.toml.

Before you deploy

• [x] I included a patch bump changeset