[Feature] Investigate support for OS login for Bigquery Dataproc Python models

[colin-rogers-dbt]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

Describe the feature

Currently if a user's GCP org specifies a constraint it can break python models with an exception like:

409 Operation denied by org policy: [constraints/compute.managed.requireOsLogin] : Preview: This constraint, when enforced, requires enablement of OS Login on all newly created Projects. On new and existing projects, this constraint 

To support this we may need to:

1. update the runtime version that we pin to 1.1
2. provide a user config to explicitly handle this behavior

Describe alternatives you've considered

No response

Who will this benefit?

No response

Are you interested in contributing this feature?

No response

Anything else?

Reference:
https://docs.cloud.google.com/compute/docs/oslogin
https://docs.cloud.google.com/dataproc-serverless/docs/release-notes#July_04_2025

Code to be update:

dbt-adapters/dbt-bigquery/src/dbt/adapters/bigquery/python_submissions.py

Lines 176 to 178 in 33f45c0

	properties={
	"spark.executor.instances": "2",
	},