digit-separators flag no longer required unless for dart formatcommand

[PiotrFLEURY]

Context

Digit separators are allowed since Dart 3.6 as mentioned in the official documentation here

This feature allow to write large number values like so

int calculate() {
  return 6_000 * 7;
}

Current behavior

The dart format command raise an error when the code contains underscores in number values

For example running command

dart format .

Will produce the output

Could not format because the source could not be parsed:

line 2, column 10 of lib/digit_separator_format.dart: This requires the 'digit-separators' language feature to be enabled.
  ╷
2 │   return 6_000 * 7;
  │          ^^^^^
  ╵
Formatted 2 files (0 changed) in 0.06 seconds.

Workaround

We need to add the --enable-experimental=digit-separators flag in order to format files

dart format --enable-experiment=digit-separators .

Output

Formatted 3 files (0 changed) in 0.05 seconds.
'digit-separators' is now enabled by default; this flag is no longer required.

Note: The --enable-experimental=digit-separators flag produce a message

'digit-separators' is now enabled by default; this flag is no longer required.

But not adding it produces a message asking for adding it. Does not sounds correct.

Expected behavior

--enable-experimental=digit-separators flag should not be required for dart format command starting on Dart 3.6

Current Dart version used

dart --version

Dart SDK version: 3.6.0 (stable) (Thu Dec 5 07:46:24 2024 -0800) on "macos_arm64"

[FMorschel]

When this is fixed, we should probably CP it too.
FYI @munificent