Jpmmcneill/snowflake type boolean

[jpmmcneill]

resolves #267

Description

snowflake component of dbt-labs/dbt-core#5875

Checklist

• I have read the contributing guide and understand what's expected of me
• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have opened an issue to add/update docs, or docs changes are not required/relevant for this PR
• I have run changie new to create a changelog entry

[dbeatty10]

@jpmmcneill this one looks like it is missing the changie entry.

[dbeatty10]

@jpmmcneill Now that dbt-labs/dbt-core#5875 has been merged, just three things and then this should be ready!

1. Click the "update branch" button (or merge the latest changes from main some other way)
2. Restore the original version of dbt-requirements.txt
3. Run changie new to add a changelog entry

If all looks good after CI runs, then we'll merge.

[jpmmcneill]

@dbeatty10 just realised there was a typo in this branch name which is why my changie didn't go through 🤦. Have added and cleaned up commit history now :)