fix: De-bump Npgsql.OpenTelemetry to work with LTS EntityFramework

[JamieDanielson]

Which problem is this PR solving?

• error when using with EFCore Encountered Exception of type MethodAccessException: Attempt by method 'Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.NpgsqlRelationalConnection.get_CurrentAmbientTransaction()' to access method 'Npgsql.NpgsqlConnection.get_Settings()' failed

Short description of the changes

• Similar to De-bump Npgsql.OpenTelemetry to 6.0.7 to avoid collisions with LTS entityframework #298 there seem to be some issues with EntityFramework with .NET 7. This reverts back to 6.0.7, but adds a bump to a later patch version of 6.0.9.
• If this indeed solves the problem, a follow-up issue should be added for separating out versions for .NET 6 and .NET 7. We don't currently include net7.0 in this package so it doesn't make sense to add that conditional block here.
• In the meantime, I added a dependabot ignore block so we don't inadvertently update again; we can remove it once we update with conditionals for .NET 7.