chore(deps): update dependency phoenix_pubsub to v2

[renovate]

This PR contains the following updates:

Package	Update	Change
phoenix_pubsub	major	== 1.1.2 -> == 2.1.3

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.

[renovate]

⚠ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: mix.lock

Command failed: docker run --rm --name=renovate_a_sidecar --label=renovate_a_child -v "/tmp/worker/f09fd6/755c4a/repos/github/mike-works/phoenix-fundamentals":"/tmp/worker/f09fd6/755c4a/repos/github/mike-works/phoenix-fundamentals" -v "/tmp/worker/f09fd6/755c4a/cache":"/tmp/worker/f09fd6/755c4a/cache" -e BUILDPACK_CACHE_DIR -e CONTAINERBASE_CACHE_DIR -w "/tmp/worker/f09fd6/755c4a/repos/github/mike-works/phoenix-fundamentals" ghcr.io/containerbase/sidecar bash -l -c "install-tool erlang 26.0.1.0 && install-tool elixir v1.14.5 && mix deps.update phoenix_pubsub"
warning: found quoted keyword "test" but the quotes are not required. Note that keywords are always atoms, even when quoted. Similar to atoms, keywords made exclusively of ASCII letters, numbers, and underscores and not beginning with a number do not require quotes
  mix.exs:52:7

warning: use Mix.Config is deprecated. Use the Config module instead
  config/config.exs:6

warning: use Mix.Config is deprecated. Use the Config module instead
  config/dev.exs:1

warning: found quoted keyword "test" but the quotes are not required. Note that keywords are always atoms, even when quoted. Similar to atoms, keywords made exclusively of ASCII letters, numbers, and underscores and not beginning with a number do not require quotes
  mix.exs:52:7

warning: use Mix.Config is deprecated. Use the Config module instead
  config/config.exs:6

warning: use Mix.Config is deprecated. Use the Config module instead
  config/dev.exs:1

warning: found quoted keyword "test" but the quotes are not required. Note that keywords are always atoms, even when quoted. Similar to atoms, keywords made exclusively of ASCII letters, numbers, and underscores and not beginning with a number do not require quotes
  mix.exs:52:7

warning: use Mix.Config is deprecated. Use the Config module instead
  config/config.exs:6

warning: use Mix.Config is deprecated. Use the Config module instead
  config/dev.exs:1

** (Mix) Hex dependency resolution failed