Updated github actions and corresponding badge in readme

Author: CoreyKaylor

.github/workflows/dotnetcoretest.yml renamed to .github/workflows/dotnet-test.yml

@@ -1,4 +1,4 @@
-name: .NET Core Tests
+name: .NET Tests
 
 on:
   push:
@@ -15,13 +15,12 @@ jobs:
 
     steps:
       - name: Checkout Lightning.NET
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup .NET Core
-        uses: actions/setup-dotnet@v3
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: |
-            6.0.x
-            7.0.x
+            9.0.x
       - name: Install dependencies
         working-directory: ${{ runner.workspace }}/Lightning.NET
         run: dotnet restore

README.md

@@ -1,7 +1,7 @@
 Lightning.NET
 =============
 
-![.NET Core Tests](https://github.com/CoreyKaylor/Lightning.NET/workflows/.NET%20Core%20Tests/badge.svg)
+![.NET Tests](https://github.com/CoreyKaylor/Lightning.NET/workflows/.NET%20Tests/badge.svg)
 
 .NET library for OpenLDAP's LMDB key-value store.