[esp8266] Exclude unused waveform code to save ~596 bytes RAM (#12690)

script/ci-custom.py

@@ -552,6 +552,8 @@ def convert_path_to_relative(abspath, current):
     exclude=[
         "esphome/components/libretiny/generate_components.py",
         "esphome/components/web_server/__init__.py",
+        # const.py has absolute import in docstring example for external components
+        "esphome/components/esp8266/const.py",
     ],
 )
 def lint_relative_py_import(fname: Path, line, col, content):