Hold heirline plugin version

Heirline had a breaking change

Once it's resolved in AstroNvim I'll revert this change

init.lua

@@ -363,8 +363,9 @@ local config = {
       --     require("lsp_signature").setup()
       --   end,
       -- },
-
+      ["rebelot/heirline.nvim"] = { commit = "556666aabb57c227cbb14a996b30b2934e5ff7b1" }
     },
+
     -- All other entries override the require("<key>").setup({...}) call for default plugins
     ["null-ls"] = function(config) -- overrides `require("null-ls").setup(config)`
       -- config variable is the default configuration table for the setup function call