Feature/7 re use new scheduled function

[taylorludwig]

Depends on https://github.com/terraform-google-modules/terraform-google-event-function/pull/38 and https://github.com/terraform-google-modules/terraform-google-scheduled-function/pull/28

Being merged and released first. Then we can update module source codes to move off of my forks.

• Updates the slo module to use the scheduled-function module now that it has proper support for waiting for local_file creations before creating the archive for the cloud function

• Updates slo-pipeline to use event-function module instead of duplicated functionality. Also relies on new local_file to archive dependency functionality

• Updates the setup and tests to pass

[taylorludwig]

We could possibly add some better tests to verify the functions work as intended.

But after applying locally I have verified both the scheduled and event driven functions are being triggered. And I do see data showing up in bigquery for the slo-pipeline

[ocervell]

LGTM