fix: Update author name and copyright in nuspec file

Author: jbrinkman

packaging/chocolatey/dotnetapidiff.nuspec

@@ -6,10 +6,10 @@
         <packageSourceUrl>https://github.com/jbrinkman/dotnet-api-diff</packageSourceUrl>
         <owners>jbrinkman</owners>
         <title>DotNet API Diff</title>
-        <authors>Josh Brinkman</authors>
+        <authors>Joe Brinkman</authors>
         <projectUrl>https://github.com/jbrinkman/dotnet-api-diff</projectUrl>
         <iconUrl>https://cdn.statically.io/gh/jbrinkman/dotnet-api-diff/main/icons/icon128.png</iconUrl>
-        <copyright>2025 Josh Brinkman</copyright>
+        <copyright>2025 Joe Brinkman</copyright>
         <licenseUrl>https://github.com/jbrinkman/dotnet-api-diff/blob/main/LICENSE</licenseUrl>
         <requireLicenseAcceptance>false</requireLicenseAcceptance>
         <projectSourceUrl>https://github.com/jbrinkman/dotnet-api-diff</projectSourceUrl>