update github ci

Author: dharmaturtle

.github/workflows/main.yml

@@ -10,9 +10,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
-    - name: Setup .NET Core
-      uses: actions/setup-dotnet@v3
+    - uses: actions/checkout@v4
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: 8.0.x
     - name: Build
       run: dotnet build -c Release "src/Hedgehog.Xunit"
     - name: Test F#

.github/workflows/pull_request.yml

@@ -10,9 +10,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
-    - name: Setup .NET Core
-      uses: actions/setup-dotnet@v3
+    - uses: actions/checkout@v4
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: 8.0.x
     - name: Build
       run: dotnet build -c Release "src/Hedgehog.Xunit"
     - name: Test F#