Enable Malt on Windows by default (#2695)

src/Configuration.jl

@@ -159,7 +159,7 @@ These options are not intended to be changed during normal use.
 
 - `run_notebook_on_load::Bool = $RUN_NOTEBOOK_ON_LOAD_DEFAULT` When running a notebook (not in Safe mode), should all cells evaluate immediately? Warning: this is only for internal testing, and using it will lead to unexpected behaviour and hard-to-reproduce notebooks. It's not the Pluto way!
 - `workspace_use_distributed::Bool = $WORKSPACE_USE_DISTRIBUTED_DEFAULT` Whether to start notebooks in a separate process.
-- `workspace_use_distributed_stdlib::Bool? = $WORKSPACE_USE_DISTRIBUTED_STDLIB_DEFAULT` Should we use the Distributed stdlib to run processes? Distributed will be replaced by Malt.jl, you can use this option to already get the old behaviour. `nothing` means: determine automatically (which is currently the same as `true`).
+- `workspace_use_distributed_stdlib::Bool? = $WORKSPACE_USE_DISTRIBUTED_STDLIB_DEFAULT` Should we use the Distributed stdlib to run processes? Distributed will be replaced by Malt.jl, you can use this option to already get the old behaviour. `nothing` means: determine automatically (which is currently `false` on Windows, `true` otherwise).
 - `lazy_workspace_creation::Bool = $LAZY_WORKSPACE_CREATION_DEFAULT`
 - `capture_stdout::Bool = $CAPTURE_STDOUT_DEFAULT`
 - `workspace_custom_startup_expr::Union{Nothing,String} = $WORKSPACE_CUSTOM_STARTUP_EXPR_DEFAULT` An expression to be evaluated in the workspace process before running notebook code.

src/evaluation/WorkspaceManager.jl

@@ -56,8 +56,7 @@ function make_workspace((session, notebook)::SN; is_offline_renderer::Bool=false
         Malt.InProcessWorker
     elseif something(
         session.options.evaluation.workspace_use_distributed_stdlib, 
-        true
-        # VERSION < v"1.8.0-0"
+        Sys.iswindows() ? false : true
     )
         Malt.DistributedStdlibWorker
     else