In the past, it has generally be the case that flutter build <foo> --config-only would generate the native tooling necessary to do native builds, and then the native builds can be used to select the configuration. For instance, it should generally be possible to flutter build ios --config-only, and then pick either Debug or Release builds in Xcode's UI. There have been edge cases, but mostly it worked.

--no-explicit-package-dependencies seems to break that with regard to plugin dev_dependencies; important build-configuration-specific build state seems to now be set during the 'generate native tooling' part of the flutter tool, which means that changing build configs without re-running flutter build with the matching config may have unexpected behavior (e.g., FTL integration tests not working).

If at all possible, the config-specific parts should be generated in the re-entrant part of the flutter tool that's called by native builds, so that they are automatically updated when the configuration changes.

(See this PR discussion for more context.)