CI: always require aws-oicd-role-arn input to be set (#10145)

## Problem
`benchmarking` job fails because `aws-oicd-role-arn` input is not set

## Summary of changes:
- Set `aws-oicd-role-arn` for `benchmarking job
- Always require `aws-oicd-role-arn` to be set
- Rename `aws_oicd_role_arn` to `aws-oicd-role-arn` for consistency

.github/actions/save-coverage-data/action.yml

@@ -14,11 +14,11 @@ runs:
         name: coverage-data-artifact
         path: /tmp/coverage
         skip-if-does-not-exist: true # skip if there's no previous coverage to download
-        aws_oicd_role_arn: ${{ inputs.aws_oicd_role_arn }}
+        aws-oicd-role-arn: ${{ inputs.aws-oicd-role-arn }}
 
     - name: Upload coverage data
       uses: ./.github/actions/upload
       with:
         name: coverage-data-artifact
         path: /tmp/coverage
-        aws_oicd_role_arn: ${{ inputs.aws_oicd_role_arn }}
+        aws-oicd-role-arn: ${{ inputs.aws-oicd-role-arn }}