Update contrib.yml

Author: emdneto

.github/workflows/contrib.yml

@@ -3,15 +3,11 @@ name: Core Contrib Test
 on:
   push:
     branches-ignore:
-      - 'release/*'
+    - 'release/*'
   pull_request:
 
-env:
-  CORE_REPO_SHA: ${{ github.sha }}
-  CONTRIB_REPO_SHA: main
-
 jobs:
   contrib_0:
-    uses: open-telemetry/opentelemetry-python-contrib/.github/workflows/core_contrib_test_0.yml@${{ env.CONTRIB_REPO_SHA }}
+    uses: open-telemetry/opentelemetry-python-contrib/.github/workflows/core_contrib_test_0.yml@main
     with:
-      CORE_REPO_SHA: ${{ env.CORE_REPO_SHA }}
+      CORE_REPO_SHA: ${{ github.sha }}