[nvim] fix: lsp count in statusline

vim.lsp.diagnostic.get_count() got deprecated

.config/nvim/lua/statusline.lua

@@ -109,7 +109,12 @@ local function get_lsp_diagnostics(bufnr)
         }
 
         for k, level in pairs(levels) do
-                result[k] = vim.lsp.diagnostic.get_count(bufnr, level)
+                local count = 0
+                local diags = vim.diagnostic.get(bufnr, { severity = level })
+                for _, _ in pairs(diags) do
+                        count = count + 1
+                end
+                result[k] = count
         end
 
         return result