DSOS-2838: instance refresh fix

[drobinson-moj]

You can't enable instance refresh if the launch template is set to $Default. Needs to be set to latest version as per AWS docs.
Regresssion tested in nomis-test (didn't break anything)
Instance refresh now working with this change in nomis-preproduction

[github-actions]

Trivy Scan Success

Show Output

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Trivy will check the following folders:

</details> #### `Checkov Scan` Success
<details><summary>Show Output</summary>

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Checkov will check the following folders:

CTFLint Scan Success

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Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.5.0)
tflint will check the following folders:

Trivy Scan Success

Show Output

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Trivy will check the following folders:

[dms1981]

Approved; looks like the unit tests still need some improvement though as they failed due to duplicate resources