Explicit `num` equality comparison doesn't account for records containing `num`s

Repro with version 2.0.8:

```dart
import 'package:equatable/equatable.dart';

void main() {
int i = 1;
double d = 1.0;
print(i == d); // prints true
print(JustNum(i) == JustNum(d)); // prints true (after PR#189)
print(NumInList([i]) == NumInList([d])); // prints true

final ri = (value: i);
final rd = (value: d);
print(ri == rd); // prints true (though incorrectly triggers unrelated_type_equality_checks lint, noted in https://github.com/dart-lang/sdk/issues/57962#issuecomment-4215639345)
print(NumInRecord(ri) == NumInRecord(rd)); // prints false
}

class JustNum with EquatableMixin {
final num value;
JustNum(this.value);

@override
List get props => [value];
}

class NumInRecord with EquatableMixin {
final ({num value}) value;
NumInRecord(this.value);

@override
List get props => [value];
}

class NumInList with EquatableMixin {
final List value;
NumInList(this.value);

@override
List get props => [value];
}

```

In `objectsEquals`, would it make sense to do something like this?

```dart
/// Determines whether two objects are equal.
@pragma('vm:prefer-inline')
bool objectsEquals(Object? a, Object? b) {
if (identical(a, b)) return true;
if (a is num && b is num) {
return numEquals(a, b);
} else if (_isEquatable(a) && _isEquatable(b)) {
return a == b;
} else if (a is Set && b is Set) {
return setEquals(a, b);
} else if (a is Iterable && b is Iterable) {
return iterableEquals(a, b);
} else if (a is Map && b is Map) {
return mapEquals(a, b);
} else if (a is Record && b is Record) { // dont check runtime type for records
return a == b;
} else if (a?.runtimeType != b?.runtimeType) {
return false;
} else if (a != b) {
return false;
}
return true;
}
```