Try to free up disk space on CI

Author: Kobzol

.github/workflows/ci.yml

@@ -104,6 +104,9 @@ jobs:
         with:
           fetch-depth: 2
 
+      - name: Free Disk Space (Ubuntu)
+        uses: jlumbroso/free-disk-space@main
+
       # 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.