Offer configs from dev.containers.repositoryConfigurationPaths and repository when both exist

          In lieu of this feature, I had been using the precedence mentioned in https://github.com/microsoft/vscode-remote-release/issues/3218#issuecomment-646636472 to do something like this workflow:

• Create a directory like ~/.config/devcontainers
• Configure the new directory in dev.containers.repositoryConfigurationPaths
• Copy a checked-out repo's .devcontainer/devcontainer.json to ~/.config/devcontainers/github.com/$ORG/$REPO/.devcontainer/
• Customize the version in ~/.config/devcontainers as needed
• Rebuild and Reopen in Container. The precedence mentioned above ensured my customized version gets used

However, this workflow seems to have stopped working — I'm not sure when, unfortunately I don't recreate my containers very often. Now, the checked-in devcontainer.json seems to take precedence over my local one (as initially proposed in https://github.com/microsoft/vscode-remote-release/issues/3218#issuecomment-646608062). I can see from the logs that the label=devcontainer.config_file refers to the repository version, rather than my local ~/.config file.

Has anyone else noticed this change / should I file a new issue for it? Without this workflow I can't seem to come up with any way at all to customize my local container, other than deleting the repository's .devcontainer folder every time I want to use it (obviously a huge pain!).

Originally posted by @ian-h-chamberlain in https://github.com/microsoft/vscode-remote-release/issues/3279#issuecomment-1692379932