Stop specifying Buildx version

[GaryGSC]

Blocked until Buildx v0.6.0 is natively available in the GitHub virtual environments, which is when this badge shows that 100% of runners are on 20210726.1, or a newer version. The percentage indicates rolling deployment progress.

Refs: #272

[github-actions]

Terraform Plan:

will create 1 resource:

• local_file - appspec_json

will update 2 resources:

• aws_s3_bucket - my_s3_bucket_logs
• aws_lambda_function - test_lambda

will replace (delete then create) 1 resource:

• aws_ecs_task_definition - task_def

see details

[GaryGSC]

This is ready for people to take a look at it, but it shouldn't be merged until that badge hits 100%.