build: update devcontainer and use latest codespaces features (#36422)

* build: update devcontainer to latest build image

* build: add update-content-command

* build: set good vscode config

* build: be less noisy in update command

* build: only run sync in prebuild environment

* build: list env vars

* build: run sync always

.devcontainer/update-content-command.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -eo pipefail
+
+buildtools=$HOME/.electron_build_tools
+
+export PATH="$PATH:$buildtools/src"
+
+# Sync latest
+e d gclient sync --with_branch_heads --with_tags