Consider falling back to %LOCALAPPDATA%\jgit\config if XDG_CONFIG_HOME is unset on Windows

[ariellourenco]

Description

This is a classic issue raised in any project. Currently JGIT stores filesystem timestamp resolution under the XDG_CONFIG_HOME directory if it is defined otherwise, it fallback $HOME/.config/jgit/config. Since neither of these are Windows-native directories JGIT ends up polluting user $HOME directory on Windows by placing an unnecessary folder. To be a better Windows citizenship, JGIT should store its filesystem timestamp resolution file on %LOCALAPPDATA% folder which is intended for use by application to store local-only data (email cache, browser cache, etc.).

See: Store filesystem timestamp resolution in extra jgit config

Motivation

Implement this change can be motivated by several key factors such as:

• Improve User Experience: By shifting to %LOCALAPPDATA%, JGIT can keep its data confined to a location that is designated for application-specific files, thereby enhancing user experience and avoid clutter in the user's home directory, which is particularly problematic for users who prefer a clean and organized file structure.
• Compliance with Windows Standards: The %LOCALAPPDATA% directory is specifically intended for applications to store local-only data. By utilizing this directory, JGIT would align itself more closely with Windows conventions.

Alternatives considered

No response

Additional context

No response