fix: loadConfig() failing with "missing loader for extension"

[tido64]

Summary:

loadConfig() failing with "missing loader for extension":

Error: Missing loader for extension "react-native.config.mjs".
    at #validateConfig (/~/node_modules/cosmiconfig/dist/ExplorerBase.js:37:23)
    at new ExplorerBase (/~/node_modules/cosmiconfig/dist/ExplorerBase.js:25:29)
    at new ExplorerSync (/~/node_modules/cosmiconfig/dist/ExplorerSync.js:16:1)
    at cosmiconfigSync (/~/node_modules/cosmiconfig/dist/index.js:138:26)
    at readConfigFromDisk (/~/node_modules/@react-native-community/cli-config/build/readConfigFromDisk.js:65:55)

Test Plan:

This is enough to trigger the error:

node -p 'require("@react-native-community/cli").loadConfig({})'

Checklist

• Documentation is up to date to reflect these changes.
• Follows commit message convention described in CONTRIBUTING.md

[tido64]

cc @szymonrybczak

[szymonrybczak]

Woah, thank you for fixing it 🙏

[szymonrybczak]

I wonder if we should add tests against loadConfig() function (reuse our old tests) 🤔