Update libgit2sharp.yml

add fetch depth

Author: lytico

.github/workflows/libgit2sharp.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
       with:
-          fetch-depth: 3
+          fetch-depth: 2
     - name: Setup .NET
       uses: actions/setup-dotnet@v1
       with: