test: update test framework to use latest best practices and reduce boilerplate

[gmeligio]

what

Update this module's test framework. Reduce boilerplate and make reusable functions.

Changelog:

1. Upgrade go to 1.21.
2. Update test/Makefile and test/src/Makefile from https://github.com/cloudposse/terraform-aws-eks-node-group/tree/e9f908c026d8ca5dc30190a050de68a510ff3983/test
3. Create framework_test.go and default_test.go, following how it's done in https://github.com/cloudposse/terraform-aws-eks-node-group/blob/e9f908c026d8ca5dc30190a050de68a510ff3983/test/src/framework_test.go
4. Remove enabled=true from fixtures and add new test TestExamplesCompleteDisabled for when enabled=false
5. Add Test_ExistingDeployment for faster test cycle, and modify Makefile accordingly
6. Update dependencies
7. Migrate test DB Engine from 3.6.0 to 5.0.0

why

• Enable testing with OpenTofu
• Support automated maintenance

references

• Closes chore(deps): update terraform cloudposse/ssm-parameter-store/aws to v0.13.0 #88
• Closes Update terratest to '>= 0.46.0' #98
• feat(aws_docdb_cluster): add allow_major_version_upgrade argument #94
• https://github.com/cloudposse/terraform-aws-eks-node-group/tree/e9f908c026d8ca5dc30190a050de68a510ff3983/test/src
• https://github.com/cloudposse/terraform-aws-dynamic-subnets/tree/8528dadc5cbdcf657faa1d917c9f069c254f41a3/test/src

[mergify]

Important

Cloud Posse Engineering Team Review Required

This pull request modifies files that require Cloud Posse's review. Please be patient, and a core maintainer will review your changes.

To expedite this process, reach out to us on Slack in the #pr-reviews channel.

[gmeligio]

/terratest

[Nuru]

/terratest

[Nuru]

/terratest

[Benbentwo]

LGTM thanks everyone

[Nuru]

@mcalhoun Has a bunch of improvements he told me he would like to see on these test (deferring more to Terratest, using more standard ways of skipping the "existing deployment" test, etc.), so let's give him a few days to make those changes.

[Nuru]

/terratest

[Nuru]

@mcalhoun Will get to fixing these tests later. This is good enough for now. I added comments about how this is work-in-progress and should not be duplicated.

[github-actions]

These changes were released in v0.26.0.