Fix recursive definition in SupportStructures.k (#4035)

This PR fixes a recursive definition issue in the `SupportStructures.kt`
file where `codegenScope` was being used within its own dependent
functions, creating a circular dependency. The issue specifically
occurred in the `serializeRedacted()`, `sensitive()`,
`configurableSerde()` and `serializeUnredacted()` functions where
`codegenScope` was being included in the template parameters.

The fix:
- Removed the recursive usage of `codegenScope`
- Instead, directly used `RuntimeType.preludeScope` where needed
- This change maintains the same functionality while avoiding the
circular dependency

Before:
```kotlin
*codegenScope  // This created a recursive definition as codegenScope depends on these functions
```

After:
```kotlin
*RuntimeType.preludeScope  // Direct usage of prelude scope without recursion
```

Co-authored-by: Fahad Zubair <fahadzub@amazon.com>