Set minimum Terraform version to 0.12.26/0.13.0

[bmelbourne]

What this PR does / why we need it:
As Terraform 0.11 is in the later stages of end-of-life (EOL), the Terraform build/test templates have been updated to be fully compatible with Terraform 0.12.26+ and 0.13.0+.

https://www.hashicorp.com/blog/deprecating-terraform-0-11-support-in-terraform-providers

Minimum Terraform AWS provider is set to v3.12.0 and Google provider is set to v3.44.0.

Which issue(s) this PR fixes
N/A

Special notes for your reviewer:
The KOPS_FEATURE_FLAGS=Terraform-0.12 will be deprecated in Kops v0.20.

Terraform reference notes regarding 0.12/0.13 provider compatibility.

https://www.terraform.io/docs/configuration/provider-requirements.html#v0-12-compatible-provider-requirements
https://www.terraform.io/upgrade-guides/0-13.html#explicit-provider-source-locations

[k8s-ci-robot]

Hi @bmelbourne. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[bmelbourne]

/hold

[hakman]

Something's not quite right with the commits.

[bmelbourne]

Something's not quite right with the commits.

It's WIP...I just needed to check the Virgin Media Web Safe settings weren't going to mess with the commits in my new branch between my forked repo and the kops upstream repo.

Just running the various tests locally and then I'll squash the commits and final rebase! 😉

[hakman]

Ah, cool. :)
/ok-to-test

[hakman]

/retest

[bmelbourne]

/assign @rifelpet

[rifelpet]

lgtm overall, just a couple comments.
#10101 creates the 1.20 release notes and mentions the feature flag removal but if we do end up requiring aws provider 3.X then we should probably mention that and link to the upgrade guide as well since it has additional instructions.

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/guides/version-3-upgrade#provider-version-configuration

[rifelpet]

/lgtm
/approve

Thanks for doing this! Feel free to /hold cancel and remove WIP from the PR title to get this merged.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bmelbourne, rifelpet

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[bmelbourne]

/unhold

[bmelbourne]

/lgtm
/approve

Thanks for doing this! Feel free to /hold cancel and remove WIP from the PR title to get this merged.

@rifelpet thanks! 😄
I was just waiting for the CI tests to complete before removing the labels.