Create bundle and publish to govcloud script

[nhulston]

What does this PR do?

Creates a job in Gitlab to bundle all the layer zips into a single zip so we no longer have to manually download each layer manually.

This PR also creates scripts/publish_govcloud_layers.sh to publish layers to either Govcloud or Govcloud staging.

Motivation

Copying logic from DataDog/datadog-lambda-extension#556

Easier testing of layers for FIPs compliance + easier time publishing to Govcloud

Testing Guidelines

Manually.

Layer bundle passed:

and produces the correct artifact as expected:

and running the script (on staging) works as expected:

ENVIRONMENT=us1-staging-fed REGIONS=us-gov-west-1 ./scripts/publish_govcloud_layers.sh <path from dragging bundle.zip file>

Additional Notes

Basically all the same logic as the datadog-lambda-extension implementation. But there is no 'flavors' since each layer works on both arm64 and amd64 Lambdas.

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog
• This PR passes the integration tests (ask a Datadog member to run the tests)

[apiarian-datadog]

let's just make sure we're not setting any unexpected or unnecessary environment variables in the publish_govcloud_layers.sh script.