Bump docker/build-push-action from 3 to 6 (#3476) #187

Job	Run time
Linting	1m 51s
Unit tests	3m 44s
Build for Linux (linux, amd64)	1m 52s
Build for Linux (linux, 386)	1m 47s
Build for Windows (windows, amd64)	3m 9s
WASM build test	0s
Initial tests passed	1s
Upgrade tests from HEAD-2	1s
Complement (${{ matrix.label }})	1s
Integration tests	1s
Sytest (${{ matrix.label }})	1s
Upgrade tests	1s
Integration tests passed	1s
Update Docker images	1s
	12m 31s

Provide feedback