Add action that frees up a bunch of memory

.github/workflows/main.yml

@@ -10,6 +10,19 @@ jobs:
       contents: read
     runs-on: ubuntu-22.04
     steps:
+      # Our workflows were running out of memory.  We don't need most of the pre-installed machinery in the
+      # github ubuntu image, so remove it using this helper action.
+      # See: https://github.com/marketplace/actions/free-disk-space-ubuntu
+      - name: Free Disk Space (Ubuntu)
+        uses: jlumbroso/free-disk-space@main
+        with:
+          tool-cache: false
+          android: true
+          dotnet: true
+          haskell: true
+          large-packages: true
+          docker-images: true
+          swap-storage: true
       - name: Checkout the Squid repo
         uses: actions/checkout@v4
       - name: Run the setup script for Ubuntu 22.04
@@ -31,4 +44,4 @@ jobs:
         working-directory: "${{ runner.temp }}/Squid/software"
       - name: Run the tests
         run: python3 -m pytest
-        working-directory: "${{ runner.temp }}/Squid/software"
+        working-directory: "${{ runner.temp }}/Squid/software"