Add additional GitHub Actions OIDC thumbprint

[lopopolo]

These changes are applied:

Terraform will perform the following actions:

  # module.github_actions_oidc_provider.aws_iam_openid_connect_provider.github will be updated in-place
  ~ resource "aws_iam_openid_connect_provider" "github" {
        id              = "arn:aws:iam::447522982029:oidc-provider/token.actions.githubusercontent.com"
        tags            = {}
      ~ thumbprint_list = [
            "6938fd4d98bab03faadb97b34396831e3780aea1",
          + "1c58a3a8518e8759bf075b76b750d4f2df264fcd",
        ]
        # (4 unchanged attributes hidden)
    }

Plan: 0 to add, 1 to change, 0 to destroy.

See: https://github.blog/changelog/2023-06-27-github-actions-update-on-oidc-integration-with-aws/
Fixes #533

[lopopolo]

Verified fixed by re-running a previously failed code coverage job:

• before (failed): https://github.com/artichoke/posix-space/actions/runs/5439193865/jobs/9891002518
• after (passed): https://github.com/artichoke/posix-space/actions/runs/5439193865/jobs/9891340895