Flag to disable latest tests (#126)

# Motivation
Form time to time, as now, the latest IC repo is no longer compatible
with the snsdemo. When that happens, the "latest" canary test goes red.
Good, it has done its job. But once the canary has died there is no
point in killing many more canaries until the gas has been cleared from
the mine.

# Changes
- Disable the latest test with an "if" so that it is visible in CI that
the latest check has been skipped.

# Tests
- See CI. You should see a grayed out "latest" test. And no failed
tests.

---------

Co-authored-by: Max Murphy-Skvorzov <[email protected]>

.github/workflows/run.yml

@@ -74,6 +74,7 @@ jobs:
           path: state.tar.xz
           retention-days: 3
   demo_latest:
+    if: false # Claim that snsdemo works with the latest IC repo commit (true) or acknowledge that it doesn't (false).
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false