fix(integration-test-deployment): Use AssumeRole instead of OIDC

OIDC is not setup in prod, and it isn't needed as we already can use the role in Codebuild to assume the Atmosphere role.

setting role-chaining lets the action use AssumeRole instead of OIDC as documented here:
https://github.com/aws-actions/configure-aws-credentials?tab=readme-ov-file#other-authentication-scenarios

Author: Abogical

.github/workflows/integration-test-deployment.yml

@@ -45,6 +45,7 @@ jobs:
           role-to-assume: ${{ vars.CDK_ATMOSPHERE_OIDC_ROLE }}
           role-session-name: run-tests@aws-cdk-deployment-integ
           aws-region: us-east-1
+          role-chaining: true
 
       - name: Setup Node.js
         uses: actions/setup-node@v5