Fix rspec and rubocop issues

[NotFounds]

When I created a pull request for #41, the CI failed in an unrelated section.

Since rspec-its and rubocop were configured to use the latest versions in the CI environment, I fixed the code to keep up with those changes.

P.S. I'm not sure about the Mermaid error. Sorry.

[Copilot]

🟢 Approval recommended

The changes are small, localized, and appear to be straightforward compatibility/style fixes without altering runtime behavior in a risky way.

Pull request overview

This PR updates the codebase to stay compatible with newer CI toolchain behavior (notably rspec-its) and resolves minor RuboCop/style issues that were causing CI failures unrelated to the functional changes in PR #41.

Changes:

• Update the Key spec to avoid its(:...) calls on private methods by asserting via send.
• Minor whitespace cleanup in the Redis provider.
• Small Ruby style modernizations (safe navigation, removing unnecessary explicit receivers).

File summaries

File	Description
spec/simplefeed/providers/serialization/key_spec.rb	Updates specs to call private methods explicitly, improving compatibility with newer rspec-its behavior.
lib/simplefeed/providers/redis/provider.rb	Removes a stray blank line/whitespace in paginate.
lib/simplefeed/providers/redis/driver.rb	Simplifies block invocation in debug output using safe navigation.
lib/simplefeed/event.rb	Removes redundant self. receivers and keeps behavior the same.

Review details

• Files reviewed: 4/4 changed files
• Comments generated: 0
• Review effort level: Lite

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.