Stop using custom version of SDK in source build

Author: wtgodbe

.azure/pipelines/ci.yml

@@ -504,16 +504,6 @@ jobs:
       chmod +x $HOME/bin/jq
       echo "##vso[task.prependpath]$HOME/bin"
     displayName: Install jq
-  - task: UseDotNet@2
-    displayName: 'Use .NET Core sdk'
-    inputs:
-      packageType: sdk
-      # The SDK version selected here is intentionally supposed to use the latest release
-      # For the purpose of building Linux distros, we can't depend on features of the SDK
-      # which may not exist in pre-built versions of the SDK
-      version: 3.0.x
-      installationPath: $(DotNetCoreSdkDir)
-      includePreviewVersions: true
   - script: ./eng/scripts/ci-source-build.sh --ci --configuration Release /p:BuildManaged=true /p:BuildNodeJs=false
     displayName: Run ci-source-build.sh
   - task: PublishBuildArtifacts@1

eng/scripts/ci-source-build.sh

@@ -9,27 +9,6 @@ set -euo pipefail
 scriptroot="$( cd -P "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 reporoot="$(dirname "$(dirname "$scriptroot")")"
 
- # For local development, make a backup copy of this file first
-if [ ! -f "$reporoot/global.bak.json" ]; then
-    mv "$reporoot/global.json" "$reporoot/global.bak.json"
-fi
-
- # Detect the current version of .NET Core installed
-export SDK_VERSION=$(dotnet --version)
-echo "The ambient version of .NET Core SDK version = $SDK_VERSION"
-
- # Update the global.json file to match the current .NET environment
-cat "$reporoot/global.bak.json" | \
-    jq '.sdk.version=env.SDK_VERSION' | \
-    jq '.tools.dotnet=env.SDK_VERSION' | \
-    jq 'del(.tools.runtimes)' \
-    > "$reporoot/global.json"
-
- # Restore the original global.json file
-trap "{
-    mv "$reporoot/global.bak.json" "$reporoot/global.json"
-}" EXIT
-
 export DotNetBuildFromSource='true'
 
  # Build repo tasks