fix errcheck in server/channels/app/platform/session.go (#30595)

Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>

server/.golangci.yml

@@ -96,7 +96,6 @@ issues:
         channels/app/permissions_test.go|\
         channels/app/platform/helper_test.go|\
         channels/app/platform/license.go|\
-        channels/app/platform/session.go|\
         channels/app/platform/status.go|\
         channels/app/slashcommands/command_test.go|\
         channels/app/slashcommands/helper_test.go|\