Fix up milestone actions

Author: JoeRobich

.github/workflows/close-milestone.yml

@@ -14,6 +14,8 @@ jobs:
         with:
           fetch-depth: 0
 
+      - uses: actions/setup-dotnet@v3
+
       - name: Install GitVersion
         uses: gittools/actions/gitversion/setup@v0.10.2
         with:

.github/workflows/update-milestone.yml

@@ -18,6 +18,8 @@ jobs:
           ref: ${{ github.sha }}
           fetch-depth: 0
 
+      - uses: actions/setup-dotnet@v3
+
       - name: Fetch all history for all tags and branches
         run: git fetch --prune