Revise upgrade package instructions for DNN Platform after 10.2.0 - #799

Node.js 20 actions are deprecated. The following actions are running on Node.js 20 and may not work as expected: actions/cache@v4, actions/checkout@v4. Actions will be forced to run with Node.js 24 by default starting June 2nd, 2026. Node.js 20 will be removed from the runner on September 16th, 2026. Please check if updated versions of these actions are available that support Node.js 24. To opt into Node.js 24 now, set the FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true environment variable on the runner or in your workflow file. Once Node.js 24 becomes the default, you can temporarily opt out by setting ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION=true. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\Author.cs(8,23): warning CS8618: Non-nullable property 'Login' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\Commit.cs(8,29): warning CS8618: Non-nullable property 'Author' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\CommitAuthor.cs(8,23): warning CS8618: Non-nullable property 'Date' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\Commits.cs(11,23): warning CS8618: Non-nullable property 'Author' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\Commits.cs(8,23): warning CS8618: Non-nullable property 'Commit' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\Contributor.cs(17,23): warning CS8618: Non-nullable property 'Contributions' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\Contributor.cs(14,23): warning CS8618: Non-nullable property 'HtmlUrl' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\Contributor.cs(11,23): warning CS8618: Non-nullable property 'AvatarUrl' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\Models\Contributor.cs(8,23): warning CS8618: Non-nullable property 'Login' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [D:\a\DNNDocs\DNNDocs\plugins\DNNCommunity.DNNDocs.Plugins\DNNCommunity.DNNDocs.Plugins.csproj]

Solution "D:\a\DNNDocs\DNNDocs\DNNDocs.sln" has active build configurations for the build project. Either enable SuppressBuildProjectCheck on "Build.Solution" or remove the following entries from the solution file: " - {0271F13D-3EE8-4130-A59B-1D9A08A193BA}.Debug|Any CPU.Build.0 = Debug|Any CPU - {0271F13D-3EE8-4130-A59B-1D9A08A193BA}.Release|Any CPU.Build.0 = Release|Any CPU"