tests/qtest/q35-test: Remove the obsolete test_without_smram_base test

tests/qtest/q35-test: Remove the obsolete test_without_smram_base test

With the release of QEMU 10.1, the pc-q35-4.1 machine will be older
than 6 years and thus will get disabled automatically by the
MACHINE_VER_DELETION() macro. Remove the related test to avoid
that the q35-test is failing when the machine is not available anymore.

Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>