Update GHA S3 check block to validate on the existing s3 bucket

.github/workflows/build.yml

@@ -312,9 +312,8 @@ jobs:
       - name: Check if package exists on S3
         if: ${{ inputs.upload }}
         run: |
-          src="artifacts/dist/${{ steps.package.outputs.name }}"
           dest="s3://packages-dev.internal.wazuh.com/development/wazuh/5.x/main/packages/"
-          if aws s3api head-object --bucket <some_bucket> --key <some_key>; then
+          if aws s3api head-object --bucket "$dest" --key "${{ steps.package.outputs.name }}"; then
             echo "exists=true" >> $GITHUB_OUTPUT
           else
             echo "exists=false" >> $GITHUB_OUTPUT