ci: update macOS GitHub Actions runner to macos-15

[dominicletz]

Summary

• CI: Updates the macOS job in .github/workflows/test.yml from macos-11 (deprecated) to macos-15. Asdf cache keys use the macos-15- prefix so caches are not reused across runner images.

• Lint / compile: Fixes the Mix.ensure_application!/1 compiler warning by using Application.ensure_all_started(:public_key) (Mix no longer exposes ensure_application!/1 publicly; :public_key remains in extra_applications). Resolves Credo nested too deep findings by extracting maybe_rewrite_dep_to_approot/4 in MacOS and import_webkit_entry/2 in Linux.

Related

Outdated macOS runners and CI/lint hygiene for this repository.

  

[dominicletz]

@cursor investigate and fix these linter errors:

warning: Mix.ensure_application!/1 is undefined or private
  lib/package/macos.ex:378: Desktop.Deployment.Package.MacOS.locate_uid/1

Generated desktop_deployment app
Checking 13 source files ...

  Refactoring opportunities                                                     
┃ 
┃ [F] → Function body is nested too deep (max depth is 2, was 4).
┃       lib/package/linux.ex:86:11 #(Desktop.Deployment.Package.Linux.import_webkit)
┃ [F] → Function body is nested too deep (max depth is 2, was 3).
┃       lib/package/macos.ex:97:9 #(Desktop.Deployment.Package.MacOS.release)

[cursor]

Here’s what was fixed and pushed to the same branch / PR.

Compiler warning (lib/package/macos.ex)

Mix.ensure_application!/1 is not part of the public Mix API on current versions, which triggered the warning. It’s replaced with Application.ensure_all_started(:public_key), which still ensures :public_key is running before PEM work. :public_key stays listed under extra_applications in mix.exs.

Credo nesting

• MacOS.release/1: The rewrite_deps callback no longer uses a nested if inside the anonymous function. Logic moved to maybe_rewrite_dep_to_approot/4, which calls rewrite_to_approot/4 only when should_rewrite?/2 is true (same behavior as before).
• Linux.import_webkit/2: The for body with nested if / inner for is split into import_webkit_entry/2.

Verification

mix compile --force shows no ensure_application warning; mix credo reports no issues.

Commit 81987db is on cursor/macos-runner-update-df0a and PR #14 was updated to mention these fixes.