Update to Erlang 29.0.2.

[conradwt]

This PR supports the following features:

• update to Erlang 29.0.2

[github-actions]

Docker image tag(s) pushed:

ghcr.io/conradwt/zero-to-graphql-using-elixir:gha-27527578419
ghcr.io/conradwt/zero-to-graphql-using-elixir:pr-317 

Labels added to images:

org.opencontainers.image.created=2026-06-15T06:14:47.271Z
org.opencontainers.image.description=The purpose of this example is to provide details as to how one would go about using GraphQL with the Elixir Language.
org.opencontainers.image.licenses=MIT
org.opencontainers.image.revision=d4d51acfc91953c0d3a77eee416e1fe67cb22777
org.opencontainers.image.source=https://github.com/conradwt/zero-to-graphql-using-elixir
org.opencontainers.image.title=zero-to-graphql-using-elixir
org.opencontainers.image.url=https://github.com/conradwt/zero-to-graphql-using-elixir
org.opencontainers.image.version=gha-27527578419