Adjust boolean-context tests for boolean literals

Author: kyoh86

test/diagnostics/boolean-context.lua

@@ -5,15 +5,15 @@ if <!a!> then end
 
 ---@type number
 local b
-if <!not b!> then end
+if not b then end
 
 ---@type number
 local c
 local x = <!c!> or "3"
 
 ---@type false
 local d
-local y = <!d!> and "4"
+local y = d and "4"
 
 ---@type boolean
 local e