This function ensures that file paths are expressed in a consistent and
canonical form. It first converts paths to absolute form using
fs::path_abs(), then tidies them with fs::path_tidy(), and finally quotes
them correctly based on the operating system. By default, normalizePath()
behaves differently on Windows and Linux when a file does not exist. On
Windows, it tries to construct an absolute path, while on Linux, it returns
the input path as-is (relative). To maintain consistency across platforms,
this function uses fs::path_abs() instead of normalizePath().