Update to .NET 9

- Bump version to 9.
- Run `npm audit fix`.
- Require Node.js v20+.
- Install the .NET 9 SDK for tests.

.github/workflows/build.yml

@@ -36,7 +36,7 @@ jobs:
     - name: Setup .NET SDK
       uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: '8.0.x'
+        dotnet-version: '9.0.x'
 
     - name: Test
       run: |

package.json

@@ -1,12 +1,12 @@
 {
   "name": "generator-aspnet-oauth",
-  "version": "8.0.0",
+  "version": "9.0.0",
   "description": "Yeoman generator for OAuth Providers for ASP.NET Core",
   "license": "MIT",
   "main": "app/index.js",
   "repository": "aspnet-contrib/generator-aspnet-oauth",
   "engines": {
-    "node": ">=14"
+    "node": ">=20"
   },
   "author": {
     "name": "Jerrie Pelser",