Remove 3.9 Test Run Dependency on 3.8 Test (#383)

## What does this pull request do?
Since we have [dropped Python 3.8 support and removed the associated
tests](#381),
we also need to remove the Python 3.9 test run's dependency on these 3.8
tests.

By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.

Author: yiyuan-he

.github/workflows/application-signals-e2e-test.yml

@@ -97,7 +97,6 @@ jobs:
 
   eks-py39-amd64:
     if: ${{ always() }}
-    needs: eks-py38-amd64
     uses: aws-observability/aws-application-signals-test-framework/.github/workflows/python-eks-test.yml@main
     secrets: inherit
     with: