feat(octo): add support for snacks picker (#5625)

## Description
A [PR](https://github.com/pwntester/octo.nvim/pull/858) has landed in
`octo.nvim` that adds initial support for `snacks.picker`. Enable it in
`octo.nvim` Extra if user uses `snacks.picker`.

I also changed the checks to use `has_extra`. This was needed for
`snacks.picker`, since `has("snacks.nvim")` doesn't ensure that user
also has `snacks.picker` enabled. For the others I just changed it for
conformity, but if you think there might be something wrong about that
(that I'm unable to think of), please feel free to change them back.
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## Related Issue(s)
None
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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/plugins/extras/util/octo.lua

@@ -42,12 +42,14 @@ return {
     "pwntester/octo.nvim",
     opts = function(_, opts)
       vim.treesitter.language.register("markdown", "octo")
-      if LazyVim.has("telescope.nvim") then
+      if LazyVim.has_extra("editor.telescope") then
         opts.picker = "telescope"
-      elseif LazyVim.has("fzf-lua") then
+      elseif LazyVim.has_extra("editor.fzf") then
         opts.picker = "fzf-lua"
+      elseif LazyVim.has_extra("editor.snacks_picker") then
+        opts.picker = "snacks"
       else
-        LazyVim.error("`octo.nvim` requires `telescope.nvim` or `fzf-lua`")
+        LazyVim.error("`octo.nvim` requires `telescope.nvim` or `fzf-lua` or `snacks.nvim`")
       end
 
       -- Keep some empty windows in sessions