Update workflow version to .net6

Author: Folleach

.github/workflows/publish.yml

@@ -8,11 +8,11 @@ jobs:
   tests:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Setup .NET
-      uses: actions/setup-dotnet@v1
+      uses: actions/setup-dotnet@v2
       with:
-        dotnet-version: 3.1.x
+        dotnet-version: 6.0.x
     - name: Restore dependencies
       run: dotnet restore ./GeometryDashAPI.sln
     - name: Build

.github/workflows/tests.yml

@@ -12,11 +12,11 @@ jobs:
   tests:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Setup .NET
-      uses: actions/setup-dotnet@v1
+      uses: actions/setup-dotnet@v2
       with:
-        dotnet-version: 3.1.x
+        dotnet-version: 6.0.x
     - name: Restore dependencies
       run: dotnet restore ./GeometryDashAPI.sln
     - name: Build