Release 3.0.3

Dropped the explicit target list from .eil.yml and idf_component.yml.
The component now declares support for every target that ESP-IDF provides;
the build matrix takes targets from ESP-IDF itself, so a new chip no longer
requires a change in this repository.

Part of esp-idf-lib/core#69.

Full changelog: 3.0.2...3.0.3