Set PackRelease to true in the Sqids.csproj file

So that `dotnet pack` uses the `Release` configuration as opposed to
`Debug`, which strangely enough is its default.
See:
- https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-pack
- https://learn.microsoft.com/en-us/dotnet/core/compatibility/sdk/8.0/dotnet-pack-config

Apparently the default is changing in .NET 8, but until then, we need to
explicitly specify this.

src/Sqids/Sqids.csproj

@@ -8,8 +8,9 @@
 		<OutputType>Library</OutputType>
 
 		<PackageId>Sqids</PackageId>
-		<Version>1.0.3</Version>
+		<Version>1.0.4</Version>
 		<Description>Official .NET port of Sqids. Generate short YouTube-looking IDs from numbers.</Description>
+		<PackRelease>true</PackRelease>
 		<PackageTags>Sqids;ID-generator;number-obfuscator;YouTube-ID</PackageTags>
 		<PackageIconUrl>https://raw.githubusercontent.com/sqids/sqids-dotnet/main/icon.png</PackageIconUrl>
 		<PackageIcon>icon.png</PackageIcon>