Server level permissions are not allowed

- SqlPackage or DacFx Version: 16.1.8089.0
- .NET Framework (Windows-only) or .NET Core: .NET Framework Version: 4.8.1 or later
- Environment (local platform and source/target platforms): Windows 11 | Visual Studio 2022 | SQL Server 2019

**Steps to Reproduce:**

1. Add a script with Build Action 'Build' in SSDT with the following command:
GRANT UNSAFE ASSEMBLY TO guest;
2. Build your project in SSDT and you get the error :
Severity Code Description Project File Line Suppression State
Error SQL70018: Server level permissions are not allowed.

**Did this occur in prior versions? If not - which version(s) did it work in?**

(DacFx/SqlPackage/SSMS/Azure Data Studio)

Reproduce the SSDT build on Windows 11 with SQL Server 2019 using a Build Action 'Build' script containing `GRANT UNSAFE ASSEMBLY TO guest;`. Start by tracing where DacFx validates server-level permissions; done means the reported SQL70018 behavior is resolved or clearly documented for this statement.

Written by the indexing model from the issue text.