export ENABLE_KECCAK flag in the root of crate #2005

Job	Run time
Wheel on macos-13 py-3.8	1m 30s
Checks	49s
Wheel on ubuntu-latest py-3.8	1m 53s
Wheel on windows-latest py-3.8	2m 22s
Run fuzz targets (macos-13, 3.8)	23m 52s
Run fuzz targets (ubuntu-latest, 3.8)	13m 48s
coverage	7m 2s
Unit tests (macos-13, 3.8)	9m 34s
Unit tests (ubuntu-latest, 3.8)	3m 33s
Unit tests (windows-latest, 3.8)	6m 16s
Upload to PyPI	6s
	1h 10m 45s

Provide feedback