[BUG] Fusion fails to parse var usage in `schema.yml` when vars are defined in `dbt_project.yml`

[eliasdefaria]

Describe the bug
When vars are defined in the dbt_project.yml like so:

vars:
  build_after_count: null
  build_after_period: null

and used in a schema.yml Fusion fails to parse with the following error:

error: dbt1013: YAML error: invalid type: map, expected i64
  --> models/example/schema.yml:8:18

What version of dbt Fusion is this bug in? (find out by running dbt --version) 2.0.0-preview.50

Is this a discrepancy between the dbt Fusion Engine and dbt Core? Check one.

• YES
• NO

To Reproduce

1. Go to this workspace
2. Run dbt parse

Expected behavior
Parse succeeds with var values from dbt_project.yml

Operating System and CPU Type (please complete the following information):

• Mac/Windows/Linux? Mac
• X86 or ARM? ARM

[b-per]

Would this be related to #982 as well?
It looks like there are a few issues related to var and Jinja in the repo

[eliasdefaria]

@b-per Could be, but this one turned out to be a bit of a false alarm. So I'm going to close it with this comment. We found that core also couldn't parse this project, but the error message (type inference during jinja var resolution) was different