Bump SixLabors.ImageSharp.Drawing from 1.0.0-beta15 to 1.0.0

Bumps [SixLabors.ImageSharp.Drawing](https://github.com/SixLabors/ImageSharp.Drawing) from 1.0.0-beta15 to 1.0.0.
- [Release notes](https://github.com/SixLabors/ImageSharp.Drawing/releases)
- [Commits](SixLabors/ImageSharp.Drawing@v1.0.0-beta15...v1.0.0)

---
updated-dependencies:
- dependency-name: SixLabors.ImageSharp.Drawing
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

source/POI.DiscordDotNet/POI.DiscordDotNet.csproj

@@ -29,7 +29,7 @@
         <PackageReference Include="Serilog.Sinks.Console" Version="4.1.1-dev-00917" />
         <PackageReference Include="Serilog.Sinks.File" Version="5.0.1-dev-00947" />
         <PackageReference Include="SixLabors.ImageSharp" Version="2.1.3" />
-        <PackageReference Include="SixLabors.ImageSharp.Drawing" Version="1.0.0-beta15" />
+        <PackageReference Include="SixLabors.ImageSharp.Drawing" Version="1.0.0" />
     </ItemGroup>
 
     <ItemGroup>