fix(nvs_flash): nvs_set with same key and different data type

Function now always rewrites old value under same key
regardless existing data type. Users requiring old API behaviour
can enable it by kconfig option CONFIG_NVS_LEGACY_DUP_KEYS_COMPATIBILITY

components/nvs_flash/src/nvs_page.cpp

@@ -878,7 +878,7 @@ esp_err_t Page::findItem(uint8_t nsIndex, ItemType datatype, const char* key, si
         end = ENTRY_COUNT;
     }
 
-    if (nsIndex != NS_ANY && datatype != ItemType::ANY && key != NULL) {
+    if (nsIndex != NS_ANY && key != NULL) {
         size_t cachedIndex = mHashList.find(start, Item(nsIndex, datatype, 0, key, chunkIdx));
         if (cachedIndex < ENTRY_COUNT) {
             start = cachedIndex;