Fix duplicate LANG variables in ci.yml (#32059)

Author: sebastienros

.azure/pipelines/ci.yml

@@ -779,9 +779,6 @@ stages:
       # This isn't needed in the path because build does not need to _use_ global tools.
       DOTNET_CLI_HOME: $(System.DefaultWorkingDirectory)
       DOTNET_SYSTEM_GLOBALIZATION_INVARIANT: true
-      LC_ALL: 'en_US.UTF-8'
-      LANG: 'en_US.UTF-8'
-      LANGUAGE: 'en_US.UTF-8'
     steps:
     - script: |
         source eng/common/native/common-library.sh