Update platformio.ini

should be dash instead of underscore

variants/rpipico-slowclock/platformio.ini

@@ -15,7 +15,7 @@ debug_init_cmds =
 # add our variants files to the include and src paths
 build_flags = ${rp2040_base.build_flags} 
   -DRPI_PICO
-  -Ivariants/rpipico_slowclock
+  -Ivariants/rpipico-slowclock
   -DDEBUG_RP2040_PORT=Serial2
   -DHW_SPI1_DEVICE
   -L "${platformio.libdeps_dir}/${this.__env__}/BSEC2 Software Library/src/cortex-m0plus"
@@ -25,4 +25,4 @@ lib_deps =
   ${rp2040_base.lib_deps}
 debug_build_flags = ${rp2040_base.build_flags}
   -g
-  -DNO_USB
+  -DNO_USB