I believe that we want to trigger actions/workflows when the workflow files in .github/workflows are updated; this is how we will know that they work :)
This pull request adds two examples and tests using the ESP-IDF framework:
* A test with the Arduino GFX library (which requires the arduino-esp32 library & Arduino BusIO library)
* A test without the Arduino GFX library, which can be compiled without any additional dependencies.
Having these tests helps prevent any future regressions that may break users of the ESP-IDF platform.
Version 6.1.7 was released on 2023-05-08 and all CI runs are failing with:
```
Error: Not a PlatformIO project. `platformio.ini` file has not been found in current working directory (examples/PIO_TestPatterns). To initialize new project please use `platformio project init` command
```
The new release notes are here: https://docs.platformio.org/en/latest/core/history.html#id2. Perhaps this breakage has something to do with new validation that `project working environment names ... only contain lowercase letters a-z, numbers 0-9, and special characters _ (underscore) and - (hyphen)` while this repo uses an example named `PIO_TestPatterns`?
Let's pin ourselves to a known good version so we can fix the issue and then choose when to upgrade in the future without causing unexpected breakages.
