Fix itermittent failures of test_dump01_restore_compatibility (#1159)
Fix itermittent failures of test_dump01_restore_compatibility (#1159)

The path to the dump file is longer than the PostgreSQL's limit of 63
characters, and since the test uses the full path name for the database
name, it fails, because Postgres silently truncates long names (it
issues a NOTICE response, but not an error).

Issue: #1158
edgedb/edgedb,edgedb/edgedb,edgedb/edgedb