Fix linker failure when using SPIFFS or LittleFS with Arduino as component

[blackhack]

Description of Change

This fixes this linker error:

c:/users/david/.platformio/packages/toolchain-xtensa-esp32/bin/../lib/gcc/xtensa-esp32-elf/12.2.0/../../../../xtensa-esp32-elf/bin/ld.exe: .pio\build\esp32dev\esp-idf\framework-arduinoespressif32\libframework-arduinoespressif32.a(vfs_api.o):(.literal._ZN11VFSFileImplD2Ev+0x4): undefined reference to `vtable for fs::FileImpl'

Tests scenarios

It can be tested on any of the examples of SPIFFS or LittleFS.
For some reason it only happens when using Arduino as component on the latest version which uses IDF 5.1, no idea why a normal Arduino project links fine, because we are declaring a virtual function on the base class, but not defining it in the same class, so we should create a empty definition or just make it pure-virtual.

    if(!LittleFS.begin()){
        Serial.println("LittleFS Mount Failed");
        return;
    }

[CLAassistant]

All committers have signed the CLA.

[Jason2866]

@me-no-dev For some strange reason the issue does not happen when the sdkconfig setting CONFIG_COMPILER_OPTIMIZATION_SIZE=y is set. So it does not happen with the Arduino Lib Builder.

[me-no-dev]

Nice catch! I wonder how we have not hit this before.

[tshcherban]

is this going to be cherry-picked to a 2.x release?

[Jason2866]

@tshcherban Just opened a PR for backporting this fix