Update scheduled.yaml (#1220)

part of
#1215


https://github.com/insightsengineering/teal.modules.clinical/actions/runs/10650776991/job/29522554433

```
    * Can't install dependency teal.reporter (>= 0.3.1.9004)* local::.:
    * Can't install dependency teal (>= 0.15.2.9052)
    * Can't install dependency insightsengineering/teal * insightsengineering/teal:
    * Can't install dependency teal.data (> 0.6.0.9007) (>= 0.5.1.9009) (>= 0.3.1.9004)
    * Can't install dependency teal.slice (>= 0.5.1.9009) (>= 0.3.1.9004)
  ✖ Failed to resolve dependencies. No progress. Exiting.
```

Depends on fixes on upstream
insightsengineering/setup-r-dependencies#4

Signed-off-by: Pawel Rucki <[email protected]>

.github/workflows/scheduled.yaml

@@ -75,6 +75,7 @@ jobs:
         insightsengineering/teal.data
         insightsengineering/teal.logger
         insightsengineering/teal.reporter
+        insightsengineering/teal.slice
         insightsengineering/teal.widgets
         insightsengineering/tern.gee
         insightsengineering/tern.mmrm