fix: don't panic on missing shorebird.yaml

[bryanoltman]

Description

Fixes shorebirdtech/shorebird#413

Validated by:

• Creating a new Flutter project
• Running shorebird init
• Removing shorebird.yaml
• Verifying that shorebird --local-engine-src-path=$HOME/Shorebird/engine/src --local-engine=android_release_arm64 run -- --release doesn't panic and still launches the app.

I also tested the release-patch flow to ensure that didn't break.

• Updates with_config in library/src/config.rs to
  • Return anyhow::Result<R> instead of R
  • Not panic if the config object isn't initialized
  • Return an error in the case where the config object isn't initialized
• Updates consumers of with_config to handle the possibility that with_config may return an error by propagating the error, usually to log_on_error in library/src/c_api.rs because the updater can't do much if no shorebird.yaml is provided.

Potential Future Work

• Improve use of anyhow::Error
  • Wrapping our error types in anyhow::Error::from() is pretty verbose and I suspect there's a better, more idiomatic way to use anyhow::Error. The report_launch_result_with_no_current_patch test is especially ugly.

Type of Change

• ✨ New feature (non-breaking change which adds functionality)
• 🛠️ Bug fix (non-breaking change which fixes an issue)
• ❌ Breaking change (fix or feature that would cause existing functionality to change)
• 🧹 Code refactor
• ✅ Build configuration change
• 📝 Documentation
• 🗑️ Chore

[eseidel]

let chat on vc quick.

[eseidel]

UpdateError was a dream. Probably can die now that we've teched up to anyhow.

[bryanoltman]

Filed #19 – I think we'll want to overhaul our error handling more generally as part of this.

[eseidel]

In a follow up patch, we should just make the Rust API return these errors, and the c_api responsible to log them when needed.