configure snowflake error logs in CI

[simonpcouch]

On #796's GHA runs, seeing the following:

Error ('test-driver-snowflake.R:2:3'): can connect to snowflake
Error in `test_con("SNOWFLAKE")`: ! ODBC failed with error 00000 from [Snowflake][DSI].
x  An error occurred while attempting to retrieve the error message for key 'SFPasswordNotFound' and component ID 102: Could not open error message files - Check that "/home/runner/work/odbc/odbc/.github/odbc/snowflake_odbc/lib/.github/odbc/en-US/SFMessages.xml" or "/home/runner/work/odbc/odbc/.github/odbc/snowflake_odbc/lib/.github/odbc/SFMessages_en-US.xml" exists and are accessible.
i From 'nanodbc/nanodbc.cpp:1141'.

This might either be due to the fact that the PR is from a fork and thus doesn't have access to the secret or a change in Posit's dev snowflake setup. Regardless, ought to properly to set up those log files.