Update readme #279

Job	Run time
Generate build matrix	7s
build-and-push-arena-images (images/base, base-on3.10-bullseye, on=3.10-bullseye)	2m 10s
build-and-push-arena-images (images/base, base-on3.9-bullseye, on=3.9-bullseye)	2m 11s
build-and-push-arena-images (images/base, base-on3.8-bullseye, on=3.8-bullseye)	1m 45s
build-and-push-arena-images (images/base, base-on3.7-bullseye, on=3.7-bullseye)	1m 43s
build-and-push-arena-images (images/ray_rllib, ray-rllib-on3.10-bullseye, on=3.10-bullseye)	29m 21s
build-and-push-arena-images (images/ray_rllib, ray-rllib-on3.9-bullseye, on=3.9-bullseye)	51m 53s
build-and-push-arena-images (images/ray_rllib, ray-rllib-on3.8-bullseye, on=3.8-bullseye)	28m 25s
build-and-push-arena-images (images/sheeprl, sheeprl-on3.10-bullseye, on=3.10-bullseye)	41m 55s
build-and-push-arena-images (images/sheeprl, sheeprl-on3.9-bullseye, on=3.9-bullseye)	55m 28s
build-and-push-arena-images (images/sheeprl, sheeprl-on3.8-bullseye, on=3.8-bullseye)	28m 40s
build-and-push-arena-images (images/stable-baselines, stable-baselines-on3.7-bullseye, on=3.7-bul...	8m 27s
build-and-push-arena-images (images/stable-baselines3, stable-baselines3-on3.10-bullseye, on=3.10...	41m 20s
build-and-push-arena-images (images/stable-baselines3, stable-baselines3-on3.9-bullseye, on=3.9-b...	26m 45s
build-and-push-arena-images (images/stable-baselines3, stable-baselines3-on3.8-bullseye, on=3.8-b...	32m 10s
	5h 52m 20s

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