Change error message for multiple active portals to note that it is in preview #110027
Description
The error message when multiple active portals is used currently says:
File \"asyncpg/protocol/protocol.pyx\", line 168, in prepare\nasyncpg.exceptions.FeatureNotSupportedError: unimplemented: multiple active portals not supported, please set session variable multiple_active_portals_enabled to true. Note: this feature is in preview
DETAIL: cannot perform operation sql.PrepareStmt while a different portal is open
HINT: You have attempted to use a feature that is not yet implemented.
See: https://go.crdb.dev/issue-v/40195/v23.1"
To make this more clear we should make this:
File \"asyncpg/protocol/protocol.pyx\", line 168, in prepare\nasyncpg.exceptions.FeatureNotSupportedError: warning: multiple active portals is in preview, please set session variable multiple_active_portals_enabled to true.
DETAIL: cannot perform operation sql.PrepareStmt while a different portal is open
HINT: You have attempted to use a feature that is in preview."
See: https://www.cockroachlabs.com/docs/v23.1/postgresql-compatibility#multiple-active-portals"
Jira issue: CRDB-31230
Epic CRDB-27601