pgsql: Move privilege check to the right place

Move privilege check to the right place

Now that ATExecDropConstraint doesn't recurse anymore, so it's wrong to
test privileges "during recursion" there.  Move the check to
dropconstraint_internal, which is the place where recursion occurs.

In passing, remove now-useless 'recursing' argument to
ATExecDropConstraint.

Discussion: https://postgr.es/m/202309051744.y4mndw5gwzhh@alvherre.pgsql

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ac22a9545ca906e70a819b54e76de38817c93aaf

Modified Files
--------------
src/backend/commands/tablecmds.c      | 18 ++++++++----------
src/test/regress/expected/inherit.out | 21 +++++++++++++++++++++
src/test/regress/sql/inherit.sql      | 21 +++++++++++++++++++++
3 files changed, 50 insertions(+), 10 deletions(-)