pgsql: Revert "Add support for Kerberos credential delegation"

Revert "Add support for Kerberos credential delegation"

This reverts commit 3d4fa227bce4294ce1cc214b4a9d3b7caa3f0454.

Per discussion and buildfarm, this depends on APIs that seem to not
be available on at least one platform (NetBSD). Should be certainly
possible to rework to be optional on that platform if necessary but bit
late for that at this point.

Discussion: https://postgr.es/m/3286097.1680922218@sss.pgh.pa.us

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/3d03b24c350ab060bb223623bdff38835bd7afd0

Modified Files
--------------
contrib/dblink/dblink.c | 127 ++++------
contrib/dblink/expected/dblink.out | 4 +-
contrib/postgres_fdw/connection.c | 72 ++----
contrib/postgres_fdw/expected/postgres_fdw.out | 19 +-
contrib/postgres_fdw/option.c | 6 -
contrib/postgres_fdw/sql/postgres_fdw.sql | 3 +-
doc/src/sgml/config.sgml | 17 --
doc/src/sgml/dblink.sgml | 5 +-
doc/src/sgml/libpq.sgml | 41 ---
doc/src/sgml/monitoring.sgml | 9 -
doc/src/sgml/postgres-fdw.sgml | 7 +-
src/backend/catalog/system_views.sql | 3 +-
src/backend/foreign/foreign.c | 1 -
src/backend/libpq/auth.c | 13 +-
src/backend/libpq/be-gssapi-common.c | 53 ----
src/backend/libpq/be-secure-gssapi.c | 26 +-
src/backend/utils/activity/backend_status.c | 1 -
src/backend/utils/adt/pgstatfuncs.c | 21 +-
src/backend/utils/init/postinit.c | 8 +-
src/backend/utils/misc/guc_tables.c | 10 -
src/backend/utils/misc/postgresql.conf.sample | 1 -
src/include/catalog/pg_proc.dat | 6 +-
src/include/libpq/auth.h | 1 -
src/include/libpq/be-gssapi-common.h | 3 -
src/include/libpq/libpq-be.h | 2 -
src/include/utils/backend_status.h | 1 -
src/interfaces/libpq/exports.txt | 1 -
src/interfaces/libpq/fe-auth.c | 15 +-
src/interfaces/libpq/fe-connect.c | 17 --
src/interfaces/libpq/fe-secure-gssapi.c | 23 +-
src/interfaces/libpq/libpq-fe.h | 1 -
src/interfaces/libpq/libpq-int.h | 2 -
src/test/kerberos/Makefile | 3 -
src/test/kerberos/t/001_auth.pl | 331 +++----------------------
src/test/perl/PostgreSQL/Test/Utils.pm | 27 --
src/test/regress/expected/rules.out | 11 +-
36 files changed, 136 insertions(+), 755 deletions(-)