`float` value validation isn't right, accepts invalid values

Nobody has claimed this yet.

```proto
edition = "2024";

message Foo {
repeated float fs = 1;
}
```
```dart
import 'test.pb.dart';

void main() {
final foo = Foo();
foo.fs.add(0.123456789);
print(foo);
print(Foo.fromBuffer(foo.writeToBuffer()));
}
```

Prints:

```
fs: 0.123456789
fs: 0.12345679104328156
```

This is because the value being set isn't valid float, but the validation function isn't correct and accepts it: https://github.com/google/protobuf.dart/blob/27730dbb6edd7e621141353b0e19eab6d6cada3a/protobuf/lib/src/protobuf/field_error.dart#L140-L143

In this particular case, it doesn't handle the numbers between the min. and max. specified by this function, but are have more fractional digits that a 32-bit float can represent. There could be other bugs too.

Ideally you would convert the number to a float and back to a double, and check that you get the same number back, but we can't easily to this in Dart. Not sure if there's a performant way to do it, without writing the number to a `Float32List` or a `ByteData` and reading it back.

Reproduce the issue with the provided proto and Dart example, then inspect protobuf/lib/src/protobuf/field_error.dart around lines 140-143. Determine how a Dart value can be checked against float32 precision, including the fractional values currently accepted. Done means values that cannot round-trip as 32-bit floats are rejected while valid float values remain accepted.

Written by the indexing model from the issue text.