[BUG] Support AWS credential detection from environment variable for OIDC temporary token

[toto6038]

Version

redhat-actions/push-to-registry@v2
aws-actions/configure-aws-credentials@v4

Describe the bug

Currently the support to login ECR needs access token and secret access token to AWS, and the action cannot detect credentials from environment variables as aws-actions/amazon-ecr-login does. The limitation prevents the usage in runner using GitHub OIDC to authenticate with AWS since it holds a temporary credential, and making authentication with temporary credential must include the session token.

My recommendation is to take an optional input of session token, or detect credentials from environment variables as well.

Steps to reproduce, workflow links, screenshots

jobs:
  Test:
    runs-on: ubuntu-latest
    steps:
      - name: Configure AWS credentials
        id: aws-creds
        uses: aws-actions/configure-aws-credentials@v4
        with:
          role-to-assume: ${{ secrets.AWS_IAM_ROLE }}
          aws-region: ${{ secrets.AWS_REGION }}
          output-credentials: true
          special-characters-workaround: true

      - uses: redhat-actions/podman-login@v1
        with: 
          registry: ${{ secrets.AWS_ECR_REGISTRY }}
          username: ${{ steps.aws-creds.outputs.aws-access-key-id }}
          password: ${{ steps.aws-creds.outputs.aws-secret-access-key }}