ci: fix windows CI failure due to add-path deprecation

Signed-off-by: Ran Benita <ran@unusedvar.com>

.github/workflows/main.yml

@@ -76,7 +76,7 @@ jobs:
           Invoke-WebRequest -Uri https://github.com/lexxmark/winflexbison/releases/download/v2.5.23/win_flex_bison-2.5.23.zip -OutFile win_flex_bison.zip
           Expand-Archive -Path win_flex_bison.zip -DestinationPath bin
           Expand-Archive -Path ninja.zip -DestinationPath bin
-          Write-Output ("::add-path::" + (Get-Location) + "./bin")
+          Write-Output ((Get-Location).ToString() + "./bin") | Out-File -Append -FilePath $env:GITHUB_PATH -Encoding utf8
       - name: Setup
         shell: cmd
         run: |