Need a ..\ to get to the repo root

Author: dmachaj

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
           
           & "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
 
-          $repoRoot = $env:GITHUB_WORKSPACE
+          $repoRoot = $env:GITHUB_WORKSPACE\..
           Write-Host "The root of the repository is $repoRoot"
 
           & $repoRoot\find_clang_format.cmd