Remove lsp-flycheck-live-reporting setting

This variable was removed upstream.

modules/tools/lsp/+lsp.el

@@ -6,9 +6,6 @@
   (setq lsp-session-file (concat doom-etc-dir "lsp-session"))
   ;; Auto-kill LSP server after last workspace buffer is killed.
   (setq lsp-keep-workspace-alive nil)
-  ;; Let `flycheck-check-syntax-automatically' determine this. Will be removed
-  ;; soon: https://github.com/emacs-lsp/lsp-mode/pull/1701/files
-  (setq lsp-flycheck-live-reporting nil)
   ;; For `lsp-clients'
   (setq lsp-server-install-dir (concat doom-etc-dir "lsp/")
         lsp-intelephense-storage-path (concat doom-cache-dir "lsp-intelephense/"))