feat: add terraform provider as submodule and configure upstream script

[ocobles]

• Configure upstream
• Upgrade dependencies:

1. golangci-lint v1.55.2
2. gradle-version 7.6
3. pulumi java generator v0.9.8
4. pulumi sdk v3.91.1
5. terraform provider v1.18.2

• Patch upstream to add a Pulumi user-agent (I have added this patch as a test to prove that it works correctly, but I will open some issues for other necessary patches, for example to eliminate references to terraform documentation)
• I have added gh actions to upgrade pulumi-terraform-bridge and provider, but it will require configuring a bot to be able to do it automatically

[github-actions]

Does the PR have any schema changes?

Does the PR have any schema changes?

Found 1 breaking change:

Types

• 🟢 "equinix:metal/getDevicesDevice:getDevicesDevice": required: "sosHostname" property has changed to Required
  No new resources/functions.

Maintainer note: consult the runbook for dealing with any breaking changes.

[displague]

Is this necessary? I imagine this may only be necessary for providers that have their Provider definition locked away behind internal/.

In the Equinix TF Provider we intend to keep the Provider definition in the public equinix/ directory, as we move the resource definitions themselves to internal/.

https://github.com/equinix/terraform-provider-equinix/blob/main/equinix/provider.go#L47

[ocobles]

@displague we could really go ahead without this, but the main intention is to have the ability to patch the upstream terraform provider https://github.com/pulumi/pulumi-linode/blob/45f0351a1026bc7d44234f365f0308e7884da343/scripts/upstream.sh#L96

For example to replace references to terraform registry that doesn't make sense in Pulumi documentation

[ctreatma]

I'm trusting CI a bunch here; the combination of a bunch of different upgrades makes it hard to tease out what caused the various code changes. If we can, it would be nice to upgrade fewer things per PR in the future.