Bash full linting (tech debt)

[rlhagerm]

This story is to address tech debt and failing linting after PR #5811. Complete when full linting passes.

[brmur]

@meyertst-aws Can you evaluate whether changes are needed to the linter for Bash, as it may be too strict at the moment.

[DavidSouther]

https://github.com/awsdocs/aws-doc-sdk-examples/actions/runs/7543595843/job/20534972544

Some of these are real errors:

So Tools Team can go in and fix those in the .tools/.github directories.

Some of these are a pattern in the aws-cli code:

Which I disagree with the finding, checking two things and capturing RESPONSE in that check would be onerous. So if that's a pattern @meyertst-aws approves of and uses often, let's add SC2028 to the exclusion list in https://github.com/awsdocs/aws-doc-sdk-examples/blob/main/aws-cli/bash-linux/.shellcheckrc (docs: https://www.shellcheck.net/wiki/Directive)