tests/tcg: clean-up gdb confirm/pagination settings

tests/tcg: clean-up gdb confirm/pagination settings

We can do this all in the run-test.py script so remove the extraneous
bits from the individual tests which got copied from the original
non-CI gdb tests.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230829161528.2707696-8-alex.bennee@linaro.org>