Release v2.9.0

What's Changed

• Migrate to .NET 6 by @sean-mcl in #149

• Bump GitVersion.MsBuild from 5.6.11 to 5.7.0 in /Plotly.Blazor by @dependabot in #112

• Bump GitVersion.MsBuild from 5.7.0 to 5.8.1 in /Plotly.Blazor by @dependabot in #127

• Prevent null references on initialisation @centreboard in #148

• Bump plotly.js to 2.9.0 by @centreboard in #144

• Add plotly.toImage functionality by @sean-mcl in #151

• Add plotly.downloadImage functionality by @sean-mcl in #152

New Contributors

• @centreboard made their first contribution in #148

Full Changelog: v2.3.1...v2.9.0