Add 60 sleep to workflow

There is some sort of timing issue when spinning up the monero containers on
github CI. I do not know exactly what is the cause but we have a configurable
'additional sleep time' already available for `testcontainers` that can resolve
this issue.

Use the environment variable MONERO_ADDITIONAL_SLEEP_PERIOD to tell
`testcontainers` to wait an additional 60 while bringing up the monero
container.

.github/workflows/ci.yml

@@ -75,3 +75,5 @@ jobs:
 
       - name: Cargo test
         run: cargo test --workspace --all-features
+        env:
+          MONERO_ADDITIONAL_SLEEP_PERIOD: 60000