Exclude testing code from release builds (#15)

# Exclude testing code from release builds

## ♻️ Current situation & Problem
In #14 we forgot to exclude some testing code from release builds
resulting in a build error. This got fixed with this PR.


## ⚙️ Release Notes 
* Fixed release builds

### Code of Conduct & Contributing Guidelines 

By submitting creating this pull request, you agree to follow our [Code
of
Conduct](https://github.com/StanfordBDHG/.github/blob/main/CODE_OF_CONDUCT.md)
and [Contributing
Guidelines](https://github.com/StanfordBDHG/.github/blob/main/CONTRIBUTING.md):
- [x] I agree to follow the [Code of
Conduct](https://github.com/StanfordBDHG/.github/blob/main/CODE_OF_CONDUCT.md)
and [Contributing
Guidelines](https://github.com/StanfordBDHG/.github/blob/main/CONTRIBUTING.md).

ENGAGEHF/Dashboard/Dashboard.swift

@@ -27,6 +27,7 @@ struct Dashboard: View {
                         AccountButton(isPresented: $presentingAccount)
                     }
                 }
+#if DEBUG || TEST
                 .toolbar {
                     if FeatureFlags.testMockDevices {
                         ToolbarItemGroup(placement: .secondaryAction) {
@@ -39,6 +40,7 @@ struct Dashboard: View {
                         }
                     }
                 }
+#endif
         }
     }
 }