Akamai Terraform: akamai_cps_csr fails with unexpected EOF

## The problem

data.akamai_cps_csr fails with: could not get enrollment: fetching enrollment: request failed: unexpected EOF. The provider's CPS data source could not fetch the certificate enrollment from the Akamai API. This was an API-side problem, not a misconfigured edgerc or enrollment ID.

## The fix

Resolved by an API-side fix from Akamai: the reporter confirmed the data source works again with no provider upgrade needed. If you hit unexpected EOF from data.akamai_cps_csr, retry after a short wait before assuming your configuration is wrong; the enrollment API was intermittently returning truncated responses.