chore(deps): bump SixLabors.ImageSharp from 3.1.4 to 3.1.5 in /Backend (#296)

Bumps [SixLabors.ImageSharp](https://github.com/SixLabors/ImageSharp) from 3.1.4 to 3.1.5.
- [Release notes](https://github.com/SixLabors/ImageSharp/releases)
- [Commits](SixLabors/ImageSharp@v3.1.4...v3.1.5)

---
updated-dependencies:
- dependency-name: SixLabors.ImageSharp
  dependency-type: direct:production
...

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Backend/PoliFemoBackend.csproj

@@ -42,7 +42,7 @@
         <PackageReference Include="Mysql.Data" Version="8.3.0"/>
         <PackageReference Include="Newtonsoft.Json" Version="13.0.3"/>
         <PackageReference Include="ReverseMarkdown" Version="4.3.0"/>
-        <PackageReference Include="SixLabors.ImageSharp" Version="3.1.4"/>
+        <PackageReference Include="SixLabors.ImageSharp" Version="3.1.5"/>
         <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0"/>
         <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="7.3.1"/>
         <PackageReference Include="Microsoft.IdentityModel.Protocols.OpenIdConnect" Version="7.3.1" />