feat(root): provide vim.g.root_lsp_ignore to ignore LSP servers (#4332)

## Description
This provides `vim.g.root_lsp_ignore` for users to customize which LSP
servers should be taken into account when evaluating the LSP `root_dir`.
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## Related Issue(s)
Closes #4330
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  If this PR fixes any issues, please link to the issue here.
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## Screenshots

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## Checklist

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

lua/lazyvim/config/options.lua

@@ -40,6 +40,10 @@ vim.g.lazyvim_statuscolumn = {
 -- * powershell
 -- LazyVim.terminal.setup("pwsh")
 
+-- Set LSP servers to be ignored when used with `util.root.detectors.lsp`
+-- for detecting the LSP root
+vim.g.root_lsp_ignore = { "copilot" }
+
 -- Hide deprecation warnings
 vim.g.deprecation_warnings = false