fix(vim.net): filetype detection, mark unmodified #36297

Problem:
When running ":edit <url>", filetype detection is not triggered.

Solution:
Run the autocmds in the filetypedetect group after loading the content.

Problem:
After fetching remote content from a URL and adding it to the buffer,
the buffer is marked as modified. This is inconsistent with the original
netrw behavior, and it causes problems with `:e` to refresh or `:q` as
it prompts for saving the file even if the user hasn't touched the
content at all.

Solution:
Mark the buffer as unmodified right after adding the remote content to
the buffer.

runtime/plugin/nvim/net.lua

@@ -28,6 +28,8 @@ local function on_remote_read(args)
 
       local lines = vim.split(content.body, '\n', { plain = true })
       vim.api.nvim_buf_set_lines(bufnr, 0, -1, true, lines)
+      vim.api.nvim_exec_autocmds('BufRead', { group = 'filetypedetect', buffer = bufnr })
+      vim.bo[bufnr].modified = false
 
       vim.fn.winrestview(view)
       vim.api.nvim_echo({ { 'Loaded ' .. url, 'Normal' } }, true, {})