fix(build): only load the plugin before build for `:` build commands

lua/lazy/manage/task/plugin.lua

@@ -19,6 +19,9 @@ local B = {}
 ---@param task LazyTask
 ---@param build string
 function B.cmd(task, build)
+  if task.plugin.build ~= "rockspec" then
+    Loader.load(task.plugin, { task = "build" })
+  end
   local cmd = vim.api.nvim_parse_cmd(build:sub(2), {}) --[[@as vim.api.keyset.cmd]]
   task:log(vim.api.nvim_cmd(cmd, { output = true }))
 end
@@ -48,10 +51,6 @@ M.build = {
   run = function(self)
     vim.cmd([[silent! runtime plugin/rplugin.vim]])
 
-    if self.plugin.build ~= "rockspec" then
-      Loader.load(self.plugin, { task = "build" })
-    end
-
     local builders = self.plugin.build
 
     -- Skip if `build` is set to `false`