runner.py fails to use temporary Goose config on Windows

[ct-parker]

On Windows, runner.py fails to use the temporary .config/goose/config.yaml and instead loads the config from the user's home directory.

Notes:

• There appears to be an unnecesary duplicate path element in the working directory (i.e., eval_workdir/claude-sonnet_goose_PMID_28027860_Full_Text_artl/eval_workdir\claude-sonnet_goose_PMID_28027860_Full_Text).
• The method runner.py currently uses to create the working directory relies on unix-specific paths.
• On MacOS and Linux, "." can refer to current working directory. This does not work on Windows.
• Windows uses %APPDATA%\Block\goose\config\config.yaml.
• MacOS and Linux use $HOME/.config/goose/config.yaml.
• runner.py uses whichever goose appears first in the PATH, but does not indicate (for debugging purposes) where that file is. This is confounding debugging when multiple goose installations exist on a system.
• Some output looks like path names, which makes troubleshooting more complicated (i.e., Progress: 3/3 - goose/claude-sonnet/PMID_28027860_Full_Text does not actually a path name but rather a server combination).