Because
flutter_html >=2.0.0-nullsafety.1 <3.0.0-alpha.1 depends on flutter_svg >=0.22.0 <1.0.0
and my-project depends on flutter_svg ^2.0.5, flutter_html >=2.0.0-nullsafety.1 <3.0.0-alpha.1 is forbidden.
So, because my-project depends on flutter_html ^2.0.0, version solving failed.
Migrate on flutter_svg ^2.0.0