ci: remove spi_flash_qio_s2 config

This config is already run for all targets in spi_flash_qio config

tools/unit-test-app/configs/spi_flash_qio_s2

@@ -1,3 +0,0 @@
-TEST_COMPONENTS=spi_flash
-CONFIG_ESPTOOLPY_FLASHMODE_QIO=y
-CONFIG_IDF_TARGET="esp32s2"