sql: remove test gh-3733-pragma.test.lua

@TarantoolBot document
Title: changes in EXPLAIN and PRAGMA

The most important change is that the column names for
the result of the "EXPLAIN ...", "EXPLAIN QUERY PLAN ..."
and "PRAGMA ..." commands are now defined.
Example:
box.cfg{listen = 3302}
cn = require('net.box').connect(box.cfg.listen)
cn:execute('EXPLAIN SELECT 1;')

In addition, the 'case_sensitive_like', 'parser_trace' and
'sql_default_engine' pragmas now return their values if
they are executed without arguments. For the first two
pragmas, this value is their state, and for the latter,
the default engine currently set in SQL.
Example:
box.sql.execute('PRAGMA case_sensitive_like;')

And the last change is that now the execution of the
“PRAGMA” command without determining which pragma to
execute returns status for all flag-type pragmas.
Flag-type pragmas are pragmas that have TRUE or FALSE as
status.
Example:
box.sql.execute('PRAGMA;')