Standardize on PostgreSQL, remove SQL Server and MySQL

[wendellmva]

Summary

Standardize the database layer on PostgreSQL and remove SQL Server and MySQL providers.

Tasks

• Update Npgsql.EntityFrameworkCore.PostgreSQL to 9.0.0
• Add timestamp behavior switch in Program.cs
• Update default configuration to use PostgreSQL
• Delete src/BaGet.Database.SqlServer/ project
• Delete src/BaGet.Database.MySql/ project
• Remove projects from BaGet.sln
• Generate new EF Core migration for PostgreSQL
• Keep SQLite for development/testing

Files to Modify

• src/BaGet.Database.PostgreSql/BaGet.Database.PostgreSql.csproj
• src/BaGet/Program.cs
• src/BaGet/appsettings.json
• BaGet.sln

Default Configuration

{
  "Database": {
    "Type": "PostgreSql",
    "ConnectionString": "Host=localhost;Database=baget;Username=baget;Password=baget"
  }
}

Dependencies

• Depends on .NET 9 upgrade