Auto merge of #144305 - ChrisDenton:win-free-disk-space, r=marcoieni

Free disk space on Windows 2025 runners

I've managed to reduce the time deletion takes by:

 - Using powershell, which is generally faster for filesystem operations than msys2
 - Performing deletions concurrently then waiting for them all to complete

It still takes 2-10 mins but that's not too bad.

.github/workflows/ci.yml

@@ -117,7 +117,7 @@ jobs:
         with:
           fetch-depth: 2
 
-      # Free up disk space on Linux by removing preinstalled components that
+      # Free up disk space on Linux and Windows by removing preinstalled components that
       # we do not need. We do this to enable some of the less resource
       # intensive jobs to run on free runners, which however also have
       # less disk space.
@@ -125,6 +125,13 @@ jobs:
         run: src/ci/scripts/free-disk-space.sh
         if: matrix.free_disk
 
+      # If we don't need to free up disk space then just report how much space we have
+      - name: print disk usage
+        run: |
+          echo "disk usage:"
+          df -h
+        if: matrix.free_disk == false
+
       # Rust Log Analyzer can't currently detect the PR number of a GitHub
       # Actions build on its own, so a hint in the log message is needed to
       # point it in the right direction.