treewide: migrate to pluginRC for correct DAG order

The "new" DAG order is as follows:
- (luaConfigPre)
- globalsScript
- basic
- theme
- pluginConfigs
- extraPluginConfigs
- mappings
- (luaConfigPost)

modules/plugins/dashboard/alpha/config.nix

@@ -16,7 +16,7 @@ in {
 
     # the entire credit for this dashboard configuration to https://github.com/Rishabh672003
     # honestly, excellent work
-    vim.luaConfigRC.alpha = entryAnywhere ''
+    vim.pluginRC.alpha = entryAnywhere ''
       local alpha = require("alpha")
       local plenary_path = require("plenary.path")
       local dashboard = require("alpha.themes.dashboard")