[release/6.0] Work around #41937

- unset `ASPNETCORE_ENVIRONMENT` on Helix agents

eng/helix/content/runtests.cmd

@@ -18,6 +18,9 @@ set InstallPlaywright=%$installPlaywright%
 set PLAYWRIGHT_BROWSERS_PATH=%CD%\ms-playwright
 set PLAYWRIGHT_DRIVER_PATH=%CD%\.playwright\win-x64\native\playwright.cmd
 
+REM Avoid https://github.com/dotnet/aspnetcore/issues/41937 in current session.
+set ASPNETCORE_ENVIRONMENT=
+
 set "PATH=%HELIX_WORKITEM_ROOT%;%PATH%;%HELIX_WORKITEM_ROOT%\node\bin"
 echo Set path to: "%PATH%"
 echo.

eng/helix/content/runtests.sh

@@ -13,6 +13,9 @@ DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 export DOTNET_MULTILEVEL_LOOKUP=0
 export DOTNET_SKIP_FIRST_TIME_EXPERIENCE=1
 
+# Avoid https://github.com/dotnet/aspnetcore/issues/41937 in current session.
+unset ASPNETCORE_ENVIRONMENT
+
 export PATH="$PATH:$DIR:$DIR/node/bin"
 
 # Set playwright stuff