Add 'condition: always()' to Disk Usage after Build (#44209)

Looking at builds like this: https://dev.azure.com/dnceng/public/_build/results?buildId=873478&view=logs&j=1f8f000c-1adc-5434-677a-95dd9e006aba&t=30ef7da5-6e59-540d-0dbe-fa78537a8165&s=d654deb9-056d-50a2-1717-90c08683d50a, the other legs are failing left and right filling the agents' disks.  We need to know the disk usage after a build to see if this is relevant to build failures.

eng/pipelines/common/global-build-job.yml

@@ -88,6 +88,7 @@ jobs:
           du -sh $(Build.SourcesDirectory)/*
           df -h
         displayName: Disk Usage after Build
+        condition: always()
 
       # If intended to send extra steps after regular build add them here.
     - ${{ if ne(parameters.extraStepsTemplate, '') }}: