change group to tags in task `eus_exams` task configs (#2320)

lm_eval/tasks/eus_exams/README.md

@@ -26,7 +26,7 @@ Homepage: https://github.com/hitz-zentroa/latxa
 
 ### Groups and Tasks
 
-#### Groups
+#### Tags
 
 * `eus_exams_eu`: The Basque version of the exams.
 * `eus_exams_es`: The Spanish version of the exams.

lm_eval/tasks/eus_exams/eus_exams_es

 include: eus_exams
-group:
+tag:
   - eus_exams_es
 doc_to_text: "Pregunta: {{question}}\nA: {{candidates[0]}}\nB: {{candidates[1]}}\nC: {{candidates[2]}}\nD: {{candidates[3]}}\nRespuesta:"

lm_eval/tasks/eus_exams/eus_exams_eu

 include: eus_exams
-group:
+tag:
   - eus_exams_eu
 doc_to_text: "Galdera: {{question}}\nA: {{candidates[0]}}\nB: {{candidates[1]}}\nC: {{candidates[2]}}\nD: {{candidates[3]}}\nErantzuna:"