CI updates

Rename matrix.os to runs-on.
Opt out of dotnet telemetry.
Upgrade checkout and upload-artifact to v3.
Upgrade setup-dotnet to v2.

.github/workflows/build.yml

@@ -15,26 +15,28 @@ on:
 
 jobs:
   build:
-    name: .NET on ${{ matrix.os }} (${{ matrix.configuration }})
-    runs-on: ${{ matrix.os }}
+    name: .NET on ${{ matrix.runs-on }} (${{ matrix.configuration }})
+    runs-on: ${{ matrix.runs-on }}
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, ubuntu-latest, windows-latest]
+        runs-on: [macos-latest, ubuntu-latest, windows-latest]
         configuration: [Release, Debug]
+    env:
+      DOTNET_CLI_TELEMETRY_OPTOUT: 1
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Setup .NET Core
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v2
         with:
-          dotnet-version: '6.0.x'
+          dotnet-version: 6.0.x
 
       - name: Build
         run: dotnet publish -c ${{ matrix.configuration }} -o artifacts
 
       - name: Upload artifact
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v3
         if: matrix.configuration == 'Release'
         with:
           name: DepotDownloader-${{ runner.os }}