pgsql: Go back to suppressing foreign_data DETAIL test output.

Go back to suppressing foreign_data DETAIL test output.

This is almost a straight revert of commit fff518d, which itself was a
revert of 7d3bf73ac.

It turns out that commit 8aa9dd74, which sorted dependent objects before
deletion in DROP OWNED BY, was not sufficient to make all remaining
unstable DETAIL output stable. Unstable DETAIL output from DROP ROLE
was not affected, because that happens to use a different code path. It
doesn't seem worthwhile to fix the other code path at this time.

Discussion: https://postgr.es/m/6226.1553274783@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/09963cedced7ffb98a06298cc16305767fd2b4dd

Modified Files
--------------
src/test/regress/expected/foreign_data.out | 6 +++---
src/test/regress/sql/foreign_data.sql | 4 +++-
2 files changed, 6 insertions(+), 4 deletions(-)