Remove output (not answer) files from memory accounting TINC

They were leftover from the Perforce repo, and they should never have
been checked in. Now this normally wouldn't have been an issue, except
for commit history cleanliness: we would just silently overwrite the
output files with actual output. But what if in CI those "output files"
have different permissions? Turns out we would silently leave them
alone. Two steps down the road we have a diff failure ...

This commit removes -- at long last -- those output files.

This fix is forward-ported from an older, closed-source version of
Greenplum, where we first spotted this oversight. Strangely this is not
causing any test failures on master or 5 ... But this still should be
ported, even for cleanliness sake.
Signed-off-by: NJesse Zhang <sbjesse@gmail.com>

src/test/tinc/tincrepo/resource_management/memory_accounting/.gitignore

+/scenario/oom_test/output
+/too_many_exec_accounts/output

src/test/tinc/tincrepo/resource_management/memory_accounting/too_many_exec_accounts/output/too_many_exec_accounts.out

--- start_ignore
--- end_ignore
--- @Description Check if we create too many executor accounts
--- @author rahmaf2
--- @vlimMB 200 
-select count(distinct created_at) as fake from (select id, to_timestamp(creationdate) as created_at from minimal_mpp_25339) as test;
- fake 
-------
-    1
-(1 row)
-

src/test/tinc/tincrepo/resource_management/memory_accounting/too_many_exec_accounts/output/too_many_exec_accounts_setup.out

--- start_ignore
--- end_ignore
-drop table if exists minimal_mpp_25339;
-psql:/Users/rahmaf2/p4/original/tincrepo/resource_management/memory_accounting/too_many_exec_accounts/output/too_many_exec_accounts_setup.sql:5: NOTICE:  table "minimal_mpp_25339" does not exist, skipping
-DROP TABLE
-create table minimal_mpp_25339(id serial, creationdate bigint NOT NULL);
-psql:/Users/rahmaf2/p4/original/tincrepo/resource_management/memory_accounting/too_many_exec_accounts/output/too_many_exec_accounts_setup.sql:6: NOTICE:  CREATE TABLE will create implicit sequence "minimal_mpp_25339_id_seq" for serial column "minimal_mpp_25339.id"
-psql:/Users/rahmaf2/p4/original/tincrepo/resource_management/memory_accounting/too_many_exec_accounts/output/too_many_exec_accounts_setup.sql:6: NOTICE:  Using default RANDOM distribution since no distribution was specified.
-HINT:  Consider including the 'DISTRIBUTED BY' clause to determine the distribution of rows.
-CREATE TABLE
-insert into minimal_mpp_25339(id, creationdate) select generate_series(1, 10000000), 123456789;
-INSERT 0 10000000

src/test/tinc/tincrepo/resource_management/memory_accounting/too_many_exec_accounts/output/too_many_exec_accounts_teardown.out

--- start_ignore
--- end_ignore
-drop table minimal_mpp_25339;
-DROP TABLE