esp_wifi: Always connect Station in PMF mode if possible

While using esp_wifi_set_config, flag pmf_capable defaults to 0.
Users may not bother to enable it, which prevents connection to a
WPA3 AP. Or the AP may reset into WPA3 mode failing the re-connection.
To ensure better security, deprecate the pmf_capable flag and set it to
true internally.

examples/protocols/static_ip/main/static_ip_example_main.c

@@ -141,11 +141,6 @@ void wifi_init_sta(void)
              * However these modes are deprecated and not advisable to be used. Incase your Access point
              * doesn't support WPA2, these mode can be enabled by commenting below line */
 	     .threshold.authmode = WIFI_AUTH_WPA2_PSK,
-
-            .pmf_cfg = {
-                .capable = true,
-                .required = false
-            },
         },
     };
     ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA) );