Bump the npgsql group in /backend with 2 updates

Bumps the npgsql group in /backend with 2 updates: [Microsoft.EntityFrameworkCore](https://github.com/dotnet/efcore) and [Npgsql.EntityFrameworkCore.PostgreSQL](https://github.com/npgsql/efcore.pg).


Updates `Microsoft.EntityFrameworkCore` from 9.0.0 to 9.0.1
- [Release notes](https://github.com/dotnet/efcore/releases)
- [Commits](dotnet/efcore@v9.0.0...v9.0.1)

Updates `Npgsql.EntityFrameworkCore.PostgreSQL` from 9.0.2 to 9.0.3
- [Release notes](https://github.com/npgsql/efcore.pg/releases)
- [Commits](npgsql/efcore.pg@v9.0.2...v9.0.3)

---
updated-dependencies:
- dependency-name: Microsoft.EntityFrameworkCore
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: npgsql
- dependency-name: Npgsql.EntityFrameworkCore.PostgreSQL
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: npgsql
...

Signed-off-by: dependabot[bot] <[email protected]>

backend/Directory.Packages.props

@@ -9,7 +9,7 @@
     <AspNetCoreVersion>9.0.1</AspNetCoreVersion>
     <MassTransitVersion>8.3.4</MassTransitVersion>
     <NpgsqlVersion>9.0.2</NpgsqlVersion>
-    <NpgsqlEFCoreVersion>9.0.2</NpgsqlEFCoreVersion>
+    <NpgsqlEFCoreVersion>9.0.3</NpgsqlEFCoreVersion>
     <LeanPipeVersion>0.3.0</LeanPipeVersion>
     <AppRatingVersion>2.0.52</AppRatingVersion>
   </PropertyGroup>