e2e clusters should share the same OIDC provider

AWS has a hard limit of 100 OIDC providers globally. 
Currently each HostedCluster created by e2e creates its own OIDC provider, which results in hitting the quota limit frequently and causing the tests to fail as a result.

 
DOD:
Only a single OIDC provider should be created and shared between all e2e HostedClusters.