test: 💍 fix test on head_qa
Due to https://github.com/huggingface/datasets/issues/3758, head_qa,
config "en" is not available and makes the tests fail. The "es" is
working, so, let's use it instead.

Fixes #147 
test: 💍 fix test on head_qa: Due to https://github.com/huggingface/datasets/issues/3758, head_qa,
config "en" is not available and makes the tests fail. The "es" is
working, so, let's use it instead.

Fixes #147 