also are there any tricks to install the oidcprovider with the aws.eks.Cluster class?

can do something like this

import { OpenIdConnectProvider } from '@pulumi/aws/iam'
import { getCertificate } from '@pulumi/tls'

new OpenIdConnectProvider('foo', {
  clientIdLists: ['sts.amazonaws.com'],
  thumbprintLists: [
    eksCluster.identities.apply(async (i) =>
      getCertificate({
        url: i[0].oidcs[0].issuer,
      }),
    ).certificates[0].sha1Fingerprint,
  ],
  url: eksCluster.identities[0].oidcs[0].issuer,
})

OH so on that note, how should I install an oidc provider with a cluster created with aws.eks.Cluster?

i think it should be similar to the code i posted. just replace

eksCluster

with the variable that represents your cluster. it's not well documented because this isn't really a Pulumi issue - it's an implementation detail of the cloud provider.