fix: use utf-8 encodings for all text files

[cpacker]

The necessity to specify encoding="utf-8" in your open function calls largely depends on the environment in which your code is running. In Python, when opening a file for reading or writing, the default encoding used is platform dependent. For instance:

On Linux and macOS, the default encoding is typically UTF-8.
On Windows, it's usually not UTF-8 (more commonly CP1252 or a similar Windows-specific encoding).
If your code is expected to run in different environments, or if the files you are working with are explicitly encoded in UTF-8, it's a good practice to specify encoding="utf-8" in your open calls. This ensures consistency across different platforms and avoids potential issues with character encoding, especially when dealing with non-ASCII characters.

In summary, for both reading and writing configuration files, it's a good practice to explicitly set encoding="utf-8". This approach promotes consistency, portability, and reduces the risk of encountering encoding-related errors.

[sarahwooders]

lgtm!