Rewrite navmodeld in python (#29579)

* Added navmodeld.py

* Deleted navmodeld.cc

* Write SConscript config flags to config.py

* Remove deleted files from release/files_common

* Some more bug fixes

* Added config.py to gitignore

* Get rid of config.py

* Use set_realtime_priority

* A tiny bit more cleanup

* set realtime priority 1

* Use ModelRunner helper class from runners/__init__.py

* Formatting fixes

* mama mia that's a SPICY memory leak
old-commit-hash: 0c0af682a1

selfdrive/modeld/SConscript

@@ -69,11 +69,6 @@ lenv.Program('_dmonitoringmodeld', [
     "models/dmonitoring.cc",
   ]+common_model, LIBS=libs + snpe_lib)
 
-lenv.Program('_navmodeld', [
-    "navmodeld.cc",
-    "models/nav.cc",
-  ]+common_model, LIBS=libs + snpe_lib)
-
 # Build thneed model
 if arch == "larch64" or GetOption('pc_thneed'):
   fn = File("models/supercombo").abspath