py/mkrules, esp32: Use better build settings for ESP32-C3.

[agatti]

ESP32-C3 is not Xtensa-based, so build settings are now tailored a bit better following that fact. ESP-IDF 5.x already adds architecture-specific modules by itself so there is no need to specify either the xtensa or the riscv module in the build settings.

[github-actions]

Code size report:

   bare-arm:    +0 +0.000% 
minimal x86:    +0 +0.000% 
   unix x64:    +0 +0.000% standard
      stm32:    +0 +0.000% PYBV10
     mimxrt:    +0 +0.000% TEENSY40
        rp2:    +0 +0.000% RPI_PICO
       samd:    +0 +0.000% ADAFRUIT_ITSYBITSY_M4_EXPRESS

[codecov]

Codecov Report

Merging #12839 (29ec32a) into master (4cffa84) will not change coverage.
The diff coverage is n/a.

❗ Current head 29ec32a differs from pull request most recent head 95ce61d. Consider uploading reports for the commit 95ce61d to get more accurate results

@@           Coverage Diff           @@
##           master   #12839   +/-   ##
=======================================
  Coverage   98.39%   98.39%           
=======================================
  Files         158      158           
  Lines       20973    20973           
=======================================
  Hits        20637    20637           
  Misses        336      336           

[dpgeorge]

Thanks for the patch.