OK I found the answer. I came across PlatformIO, SPIFFS & GZIP – Spanner and Code which is spiffs but this lead me to Script for LittleFS Upload - #4 by aldope which was just changing
env.AddPreAction("$BUILD_DIR/spiffs.bin", copy_gzip_data)
to
env.AddPreAction("$BUILD_DIR/littlefs.bin", copy_gzip_data)