Docs env var info (#43150)

enterprise/backend/src/metabase_enterprise/audit_db.clj

enterprise/backend/src/metabase_enterprise/llm/settings.clj

...src/metabase_enterprise/sso/integrations/sso_settings.clj

src/metabase/cmd/resources/other-env-vars.md

src/metabase/driver/util.clj

src/metabase/models/login_history.clj

src/metabase/public_settings.clj

src/metabase/query_processor/middleware/constraints.clj

src/metabase/server/middleware/auth.clj

src/metabase/server/middleware/session.clj

src/metabase/task/truncate_audit_tables.clj

test/metabase/cmd/env_var_dox_test.clj