Revert "Update action.yml (#19416)" (#19450)

This reverts commit 78fb528.

Author: supertopher

.github/actions/start-aws-runner/action.yml

@@ -12,7 +12,7 @@ inputs:
  default: "ami-005924fb76f7477ce"
  required: true
  ec2-instance-type:
- default: "c6a.4xlarge"
+ default: "c5.2xlarge"
  required: true
  subnet-id:
  default: "subnet-0469a9e68a379c1d3"