[diag] build failure due to undefined reference to `__wrap_esp_log_writev'

[ttzeng]

Since the latest Arduino Core ESP32 version (3.3.0) needs to be built with ESP-IDF v5.5, the diag project starts failing to build due to the following error. This similar symptom was reported if WiFi is enabled, and the resolution is to enable external diag logs to avoid errors by configuring CONFIG_DIAG_USE_EXTERNAL_LOG_WRAP=y explicitly.

/home/tzeng/.espressif/tools/riscv32-esp-elf/esp-14.2.0_20241119/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/14.2.0/../../../../riscv32-esp-elf/bin/ld: esp-idf/esp_wifi/libesp_wifi.a(esp_adapter.c.obj): in function `esp_log_writev_wrapper':
/home/tzeng/Workspace/esp/esp-idf/components/esp_wifi/esp32c3/esp_adapter.c:358:(.text.esp_log_writev_wrapper+0x4): undefined reference to `__wrap_esp_log_writev'