v7.4.0

What's Changed

• Fixed HumidAir.Mixing method by @portyanikhin in #324
• Updated target frameworks to .NET Standard 2.0/2.1 and .NET 9.0 by @portyanikhin in #325
• Bump UnitsNet and UnitsNet.NumberExtensions from 5.59.0 to 5.61.0 by @dependabot in #323
• Bump csharpier from 0.29.2 to 0.30.3 by @dependabot in #321

Full Changelog: v7.3.0...v7.4.0