fix(ui): don't disable search mode if empty pattern and last-pattern is set (#1445)

Author: williamboman

lua/mason/ui/instance.lua

@@ -156,7 +156,7 @@ window.events:on("search:enter", function()
 end)
 
 window.events:on("search:leave", function(search)
-    if search == "" then
+    if search == "" and vim.fn.getreg "/" == "" then
         mutate_state(function(state)
             state.view.is_searching = false
         end)