fix(GROW-2950): disable use of gcp storage audit from generate

[ipcrm]

Summary

Disable the ability to generate GCP audit log integration that use the previous storage method. Only generate pub/sub style gcp audit log integrations.

How did you test this change?

Validated tests run successfully and ran through manual generation; the delta (new vs old):

diff /home/coder/lacework/gcp/main.tf /home/coder/lacework/gcp/main.tf.old
41,42c41,42
<   source                       = "lacework/pub-sub-audit-log/gcp"
<   version                      = "~> 0.2"
---
>   source                       = "lacework/audit-log/gcp"
>   version                      = "~> 3.4"

Issue

https://lacework.atlassian.net/browse/GROW-2950