rollback changes in contrib

Signed-off-by: emdneto <[email protected]>

Author: emdneto

.github/workflows/contrib.yml

@@ -6,14 +6,9 @@ on:
     - 'release/*'
   pull_request:
 
-env:
-  CORE_REPO_SHA: ${{ github.sha }}
-  CONTRIB_REPO_SHA: main
-  PIP_EXISTS_ACTION: w
-
 jobs:
   contrib_0:
     uses: open-telemetry/opentelemetry-python-contrib/.github/workflows/core_contrib_test_0.yml@main
     with:
-      CORE_REPO_SHA: ${{ env.CORE_REPO_SHA }}
-      CONTRIB_REPO_SHA: ${{ env.CONTRIB_REPO_SHA }}
+      CORE_REPO_SHA: ${{ github.sha }}
+      CONTRIB_REPO_SHA: main