Update ci.yml

Author: ChrisDenton

.github/workflows/ci.yml

@@ -226,7 +226,7 @@ jobs:
 
       - name: Free Diskspace
         shell: pwsh
-        if: ${{ runner.os == "Windows" }}
+        if: runner.os == 'Windows'
         run: |
           Get-Volume | Out-String | Write-Host
           $dirs = 'C:\Program Files\LLVM\bin',