arrow

MINOR: [Developer] Add triage users (#14719)

This PR adds @ raulcd @ toddfarmer and me as "triage users" ([INFRA docs](https://cwiki.apache.org/confluence/display/INFRA/Git+-+.asf.yaml+features#Git.asf.yamlfeatures-AssigningexternalcollaboratorswiththetriageroleonGitHub)). This gives us permissions to manage issues.  

@ toddfarmer has been spearheading the JIRA -> Github migration and @ raulcd and me will need to work on the release and merge scripts to adapt them to the migration.

Authored-by: Jacob Wujciak-Jens <jacob@wujciak.de>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>