bug: Fix unsafe use of strncpy

While working on the MicroPython v1.20.0 update I came across the
following error:

```
$~/badgePython/components/pywpa2enterprise/modwpa2enterprise.c:25:5: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation]
     strncpy((char*) wifi_config.sta.ssid, aSsid, 32);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
```

The error message indicates that the `strncpy()` function call in the
provided code can potentially write more than 32 bytes to the
destination buffer, which could result in a buffer overflow and
undefined behavior.

To resolve this error, you can use `strlcpy()` instead of `strncpy()`.
`strlcpy()` is a safer alternative to `strncpy()`, as it guarantees
null-termination of the destination string and does not write more than
the specified destination size.

Thus, the modified version should look like this:

```c
strlcpy((char*) wifi_config.sta.ssid, aSsid, sizeof(wifi_config.sta.ssid));
```

This will copy at most `sizeof(wifi_config.sta.ssid)` bytes from `aSsid`
to `wifi_config.sta.ssid`, ensuring that the destination buffer is not
overflowed.

Author: brianredbeard

components/pywpa2enterprise/modwpa2enterprise.c

@@ -22,7 +22,7 @@ STATIC mp_obj_t mod_wpa2enterprise_connect (mp_uint_t n_args, const mp_obj_t *ar
     const char* aPassword = mp_obj_str_get_str(args[3]);
     int phase2 = mp_obj_get_int(args[4]);
     wifi_config_t wifi_config = {0};
-    strncpy((char*) wifi_config.sta.ssid, aSsid, 32);
+    strlcpy((char*) wifi_config.sta.ssid, aSsid, sizeof(wifi_config.sta.ssid));
     WIFI_SORT_ERRCHECK(esp_wifi_stop());
     WIFI_SORT_ERRCHECK(esp_wifi_set_mode(WIFI_MODE_STA) );
     WIFI_SORT_ERRCHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config) );