pgsql: Fix alter_system_table test

Fix alter_system_table test

Add workaround for disabling ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS
warning for the test that tries to create a tablespace with a reserved
name.

Discussion: https://www.postgresql.org/message-id/flat/E1iacW7-0003h6-6U%40gemulon.postgresql.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/88d45ac752ae49dbfafeb163b07381d3b8a6b601

Modified Files
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src/test/modules/unsafe_tests/expected/alter_system_table.out | 2 ++
src/test/modules/unsafe_tests/sql/alter_system_table.sql      | 2 ++
2 files changed, 4 insertions(+)