CI: Increase free space in workflow

Recently we've been running out of free space in the ubuntu 20.04
environment resulting in test failures.  This appears to be caused
by a change in the default available free space and not because of
any change in OpenZFS. Try and avoid this failure by applying a
suggested workaround which removes some unnecessary files.

https://github.com/actions/virtual-environments/issues/2840

Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11826 

.github/workflows/zfs-tests-functional.yml

@@ -44,6 +44,12 @@ jobs:
         sudo sed -i.bak 's/updates/extra updates/' /etc/depmod.d/ubuntu.conf
         sudo depmod
         sudo modprobe zfs
+        # Workaround to provide additional free space for testing.
+        #   https://github.com/actions/virtual-environments/issues/2840
+        sudo rm -rf /usr/share/dotnet
+        sudo rm -rf /opt/ghc
+        sudo rm -rf "/usr/local/share/boost"
+        sudo rm -rf "$AGENT_TOOLSDIRECTORY"
     - name: Tests
       run: |
         /usr/share/zfs/zfs-tests.sh -v -s 3G

.github/workflows/zfs-tests-sanity.yml

@@ -40,6 +40,12 @@ jobs:
         sudo sed -i.bak 's/updates/extra updates/' /etc/depmod.d/ubuntu.conf
         sudo depmod
         sudo modprobe zfs
+        # Workaround to provide additional free space for testing.
+        #   https://github.com/actions/virtual-environments/issues/2840
+        sudo rm -rf /usr/share/dotnet
+        sudo rm -rf /opt/ghc
+        sudo rm -rf "/usr/local/share/boost"
+        sudo rm -rf "$AGENT_TOOLSDIRECTORY"
     - name: Tests
       run: |
         /usr/share/zfs/zfs-tests.sh -v -s 3G -r sanity