pgsql: Make some tests more stable by adding more explicit ordering

Make some tests more stable by adding more explicit ordering

for some tests added by commit 2f094e7ac69, based on buildfarm results

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/cd8844e7db64d57554c780ec9881457c573c51ab

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