remove convert to json

Author: dmitry-shibanov

.github/workflows/build-python-packages.yml

@@ -83,7 +83,7 @@ jobs:
       - name: Prepare matrix
         shell: pwsh
         run: |
-          $matrix = ${{ fromJson(needs.generate_matrix.outputs.matrix) }} | ConvertFrom-Json
+          $matrix = ${{ fromJson(needs.generate_matrix.outputs.matrix) }}
           Write-Host matrix is $matrix
           $matrix.data.entities = $matrix.data.entities | Where-Object {$_.arch -NotMatch "arm64" -and $_.os -NotMatch "windows-2019"}
           Write-Host matrix after changes is $matrix