/usr/share/lintian/overrides/postgresql-10 is in postgresql-10 10.6-0ubuntu0.18.04.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | # We test for /usr/bin/pg_dropcluster, but run it without path
command-with-path-in-maintainer-script
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