chore(ci): temporarily peg greptimedb to `v0.4.0` to unblock CI #7991

Job	Run time
should-run	0s
Compute metadata	0s
Build baseline Vector container	0s
Confirm AWS credentials are minimally valid	0s
Build comparison Vector container	0s
Upload baseline images to ECR	0s
Upload comparison images to ECR	0s
Submit regression job	0s
Download regression analysis & upload report	0s
Determine regression status	0s
Regression Detection Suite	3s
	3s

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