fix(dap): only load mason-nvim-dap when not disabled (#3784)

## What is this PR for?
Only `require("mason-nvim-dap")` when it's not disabled
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## Does this PR fix an existing issue?
Fixes #3783
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  If this PR fixes any issues, please link to the issue here.
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## Checklist

- [x] I've read the
[CONTRIBUTING](https://github.com/LazyVim/LazyVim/blob/main/CONTRIBUTING.md)
guidelines.

lua/lazyvim/plugins/extras/dap/core.lua

@@ -49,7 +49,9 @@ return {
 
     config = function()
       -- load mason-nvim-dap here, after all adapters have been setup
-      require("mason-nvim-dap").setup(LazyVim.opts("mason-nvim-dap.nvim"))
+      if LazyVim.has("mason-nvim-dap.nvim") then
+        require("mason-nvim-dap").setup(LazyVim.opts("mason-nvim-dap.nvim"))
+      end
 
       vim.api.nvim_set_hl(0, "DapStoppedLine", { default = true, link = "Visual" })