Check master branch if not found in 'any' channel

[ThomasAunvik]

Attempted to use a tag for the master branch, but when i used any as the channel, it fails to find.

Unable to determine Flutter version for channel: any version: 3.23.0-12.0.pre architecture: x64

- name: Flutter
  uses: subosito/flutter-action@v2.16.0
  with:
    channel: any
    flutter-version-file: pubspec.yaml

Changing it to master works good, but would rather choose when to use stable or master in the yaml file if i could.

pubspec:

environment:
  sdk: ^3.3.4
  flutter: 3.23.0-12.0.pre

[lishaduck]

Changing to master doesn't seem to work anymore (perhaps because we're post-engine merge now?).
It's trying to parse the version as a git tag, but it's not a tag, it's a number.