increase waiting timeout from 5/10 to 30 seconds

[bdrung]

Some tests run into the waiting timeout on the slow and emulated riscv64 architecture, for example:

=================================== FAILURES ===================================
__________________________ T.test_crash_system_slice ___________________________

self = <tests.system.test_signal_crashes.T testMethod=test_crash_system_slice>

    @unittest.skipIf(
        get_init_system() != "systemd", "running init system is not systemd"
    )
    @skip_if_command_is_missing("systemd-run")
    @unittest.skipIf(os.geteuid() != 0, "this test needs to be run as root")
    def test_crash_system_slice(self) -> None:
        """Report generation for a protected process running in the system
        slice"""
        apport.fileutils.report_dir = self.orig_report_dir
        self.test_report = os.path.join(
            apport.fileutils.report_dir,
            f"{self.TEST_EXECUTABLE.replace('/', '_')}.{os.getuid()}.crash",
        )

        system_run = self.create_test_process(
            command="/usr/bin/systemd-run",
            args=[
                "-t",
                "-q",
                "--slice=system.slice",
                "-p",
                "ProtectSystem=true",
                self.TEST_EXECUTABLE,
            ]
            + self.TEST_ARGS,
        )
        try:
            sleep_pid = wait_for_process_to_appear(
                self.TEST_EXECUTABLE, self.running_test_executables
            )
            wait_for_sleeping_state(sleep_pid)
            os.kill(sleep_pid, signal.SIGSEGV)

>           self.wait_for_no_instance_running(self.TEST_EXECUTABLE)

/tmp/autopkgtest.RQrDHF/autopkgtest_tmp/tests/system/test_signal_crashes.py:261:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/tmp/autopkgtest.RQrDHF/autopkgtest_tmp/tests/system/test_signal_crashes.py:350: in wait_for_no_instance_running
    self.fail(f"Timeout exceeded, but {program} is still running.")
E   AssertionError: Timeout exceeded, but /usr/bin/gnusleep is still running.

So increase the waiting timeout from 5 and 10 seconds to 30 seconds.

There are multiple waiting functions but all have different conditions to wait for. Therefore is no easy way to unify them (while keeping them simple).

Bug: https://launchpad.net/bugs/2159030

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.46%. Comparing base (d9d3c9f) to head (6ead4e5).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #635      +/-   ##
==========================================
- Coverage   84.47%   84.46%   -0.01%     
==========================================
  Files         106      106              
  Lines       21053    21055       +2     
  Branches     3223     3223              
==========================================
+ Hits        17784    17785       +1     
- Misses       2792     2793       +1     
  Partials      477      477              

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.