sr: use site replicator svcacct to sign STS session tokens (#19111)

This change is to decouple need for root credentials to match between
 site replication deployments.

 Also ensuring site replication config initialization is re-tried until
 it succeeds, this deoendency is critical to STS flow in site replication
 scenario.

docs/site-replication/run-multi-site-oidc.sh

@@ -6,13 +6,10 @@ exit_1() {
 
 	echo "minio1 ============"
 	cat /tmp/minio1_1.log
-	cat /tmp/minio1_2.log
 	echo "minio2 ============"
 	cat /tmp/minio2_1.log
-	cat /tmp/minio2_2.log
 	echo "minio3 ============"
 	cat /tmp/minio3_1.log
-	cat /tmp/minio3_2.log
 
 	exit 1
 }