[Release] v0.19.1

[jtcohen6]

Right now, the develop branch of dbt:

• offers a significantly faster startup time vs. v0.19.0
• cannot be installed from setup.py alone

Let's get this into people's hands!

Beta (v0.19.1b1)

• hologram: Cut a new release that includes Changes to support integrating mashumaro into dbt core hologram#41. Upgrade (re-add) the hologram dependency in setup.py.
• dbt-mashumaro: Can we pin a git+ dependency to a GitHub tag and get pip install dbt==0.19.1b1 to work, even if dbt-mashumaro is missing from PyPi? If so, let's create a stable GitHub tag from dbt-labs/dbt-mashumaro@c25ed07, and add the git+ dependency to setup.py. If not, then we'll need to put dbt-mashumaro on PyPi.
• Release v0.19.1b1 to PyPi. If Docker or Homebrew prove difficult (given the git+ dependency), we can punt on them for now.

Final

Mashumaro: #3138

• Incorporate the addition of Union types in mashumaro==1.24
• Determine what we need from Provide options to to_dict and from_dict calls. Fatal1ty/mashumaro#32
• Figure out if there are any other missing pieces. Ideally we don't need our fork at all :)

Rest of v0.19.1 milestone

• Regression: Ephemeral-of-ephemeral compiled SQL (CTE no longer interpolated into target compiled query for ephemeral model #3056)
• Regression: BigQuery dynamic insert_overwrite ([BQ] Fix rendering for int64-type partition #3063, BigQuery insert_overwrite incremental strategy fails for day partitioned tables #3095)
• Regression: BigQuery scopes for service account + gcloud oauth (Can't access BigQuery tables whose original sources are spreadsheets on Google Drive with the oauth method #3040)
• Misc: Add tracking for resource counts (Add tracking for resource counts #3050)

dbt-release

• Fix Homebrew build relating to v0.19.1 release

[kwigley]

Thanks for the detailed steps here ! @jtcohen6