revert pkg_mode caching & tidy

Reverts "Pkg REPL: cache `pkg_mode` lookup (JuliaLang#54359)"
as this function is replaced when Pkg loads by a simpler repl switch so no caching is needed

stdlib/REPL/src/REPL.jl

@@ -1080,9 +1080,6 @@ setup_interface(
     extra_repl_keymap::Any = repl.options.extra_keymap
 ) = setup_interface(repl, hascolor, extra_repl_keymap)
 
-# we have to grab this after Pkg is loaded so cache it
-pkg_mode::Union{Nothing,LineEdit.Prompt} = nothing
-
 # This non keyword method can be precompiled which is important
 function setup_interface(
     repl::LineEditREPL,
@@ -1228,41 +1225,40 @@ function setup_interface(
         end,
         ']' => function (s::MIState,o...)
             if isempty(s) || position(LineEdit.buffer(s)) == 0
-                global pkg_mode
-                if pkg_mode === nothing
-                    LineEdit.clear_line(LineEdit.terminal(s))
-                    # use 6 .'s here because its the same width as the most likely `@v1.xx` env name
-                    print(LineEdit.terminal(s), styled"{blue,bold:({gray:......}) pkg> }")
-                    # spawn Pkg load to avoid blocking typing during loading. Typing will block if only 1 thread
-                    t_replswitch = Threads.@spawn begin
-                        pkgid = Base.PkgId(Base.UUID("44cfe95a-1eb2-52ea-b672-e2afdf69b78f"), "Pkg")
-                        REPLExt = Base.require_stdlib(pkgid, "REPLExt")
-                        if REPLExt isa Module && isdefined(REPLExt, :PkgCompletionProvider)
-                            for mode in repl.interface.modes
-                                if mode isa LineEdit.Prompt && mode.complete isa REPLExt.PkgCompletionProvider
-                                    pkg_mode = mode
-                                    break
-                                end
-                            end
-                        end
-                        if pkg_mode !== nothing
-                            buf = copy(LineEdit.buffer(s))
-                            transition(s, pkg_mode) do
-                                LineEdit.state(s, pkg_mode).input_buffer = buf
+                # print a dummy pkg prompt while Pkg loads
+                LineEdit.clear_line(LineEdit.terminal(s))
+                # use 6 .'s here because its the same width as the most likely `@v1.xx` env name
+                print(LineEdit.terminal(s), styled"{blue,bold:({gray:......}) pkg> }")
+                pkg_mode = nothing
+                # spawn Pkg load to avoid blocking typing during loading. Typing will block if only 1 thread
+                t_replswitch = Threads.@spawn begin
+                    pkgid = Base.PkgId(Base.UUID("44cfe95a-1eb2-52ea-b672-e2afdf69b78f"), "Pkg")
+                    REPLExt = Base.require_stdlib(pkgid, "REPLExt")
+                    if REPLExt isa Module && isdefined(REPLExt, :PkgCompletionProvider)
+                        for mode in repl.interface.modes
+                            if mode isa LineEdit.Prompt && mode.complete isa REPLExt.PkgCompletionProvider
+                                pkg_mode = mode
+                                break
                             end
                         end
                     end
-                    Base.errormonitor(t_replswitch)
-                    # while loading just accept all keys, no keymap functionality
-                    while !istaskdone(t_replswitch)
-                        c = read(stdin, Char)
-                        istaskdone(t_replswitch) && break
-                        edit_insert(s, c)
+                    if pkg_mode !== nothing
+                        buf = copy(LineEdit.buffer(s))
+                        transition(s, pkg_mode) do
+                            LineEdit.state(s, pkg_mode).input_buffer = buf
+                        end
                     end
-                    return
                 end
+                Base.errormonitor(t_replswitch)
+                # while loading just accept all keys, no keymap functionality
+                while !istaskdone(t_replswitch)
+                    c = read(stdin, Char)
+                    istaskdone(t_replswitch) && break
+                    edit_insert(s, c)
+                end
+            else
+                edit_insert(s, ']')
             end
-            edit_insert(s, ']')
         end,
 
         # Bracketed Paste Mode