Old migration break in EF Core 8 that worked in EF Core 7 and previous

[flindby]

Old migration generated in EF Core 2.1.0 break in EF Core 8.0.5.

In the old migration (first in our project) there is a column defined as:

MyEntityType = table.Column<int>(nullable: false, defaultValue: "")

Which has been working until now when I upgraded to .NET8/EFCore8.
If I remove defaultValue: "" the migration works as expected.

Stacktrace:

[11:01:56]      Applying 20180809120006_Initial...
Object reference not set to an instance of an object.
Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.FindCollectionMapping(RelationalTypeMappingInfo info, Type modelType, Type providerType, CoreTypeMapping elementMapping)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.<>c.<FindMappingWithConversion>b__8_0(ValueTuple`4 k, RelationalTypeMappingSource self)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd[TArg](TKey key, Func`3 valueFactory, TArg factoryArgument)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.FindMappingWithConversion(RelationalTypeMappingInfo mappingInfo, Type providerClrType, ValueConverter customConverter)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.FindMappingWithConversion(RelationalTypeMappingInfo mappingInfo, IReadOnlyList`1 principals)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.FindMapping(Type type, String storeTypeName, Boolean keyOrIndex, Nullable`1 unicode, Nullable`1 size, Nullable`1 rowVersion, Nullable`1 fixedLength, Nullable`1 precision, Nullable`1 scale)
   at Microsoft.EntityFrameworkCore.Migrations.MigrationsSqlGenerator.DefaultValue(Object defaultValue, String defaultValueSql, String columnType, MigrationCommandListBuilder builder)
   at Microsoft.EntityFrameworkCore.Migrations.SqlServerMigrationsSqlGenerator.ColumnDefinition(String schema, String table, String name, ColumnOperation operation, IModel model, MigrationCommandListBuilder builder)

EF Core version: 8.0.5
Database provider: Microsoft.EntityFrameworkCore.SqlServer
Target framework: (e.g. .NET 8.0)
Operating system: Windows 10