tests: Increase time for zebra_seg6local to look for sharp routes

tests: Increase time for zebra_seg6local to look for sharp routes

I have a test failure:
            r1.vtysh_cmd(
                "sharp install seg6local-routes {} nexthop-seg6local dum0 {} 1".format(
                    dest, context
                )
            )
            test_func = partial(
                check,
                r1,
                dest,
                manifest["out"],
            )
            success, result = topotest.run_and_expect(test_func, None, count=5, wait=1)
>           assert result is None, "Failed"
E           AssertionError: Failed
E           assert Generated JSON diff error report:
E
E             > $: d2 has the following element at index 0 which is not present in d1:
E
E             	{
E             	    "prefix": "1::1/128",
E             	    "protocol": "sharp",
E             	    "selected": true,...
E

The test output for 1::1/128:
	{
	  "1::1/128":[
	    {
	      "prefix":"1::1/128",
	      "prefixLen":128,
	      "protocol":"sharp",
	      "vrfId":0,
	      "vrfName":"default",
	      "selected":true,
	      "destSelected":true,
	      "distance":150,
	      "metric":0,
	      "queued":true,
	      "table":254,
	      "internalStatus":8,

Notice that it is still queued after 5 seconds.  Under extremely heavy system load
this is not long enough for convergence.  Also the zebra.log shows thread starvation
as well as long running tasks
2022/06/17 15:30:02 ZEBRA: [PHJDC-499N2][EC 100663314] STARVATION: task dplane_incoming_request (55b3ce0fea8b) ran for 6369ms (cpu time 0ms)
2022/06/17 15:30:02 ZEBRA: [T83RR-8SM5G] zebra 8.4-dev starting: vty@2601
2022/06/17 15:30:02 ZEBRA: [YZRX4-ZXG0C][EC 100663315] Thread Starvation: {(thread *)0x55b3ce6c15b0 arg=0x0 timer  r=-6.375     rib_sweep_route() &zrouter.sweeper from zebra/main.c:447} was scheduled to pop greater than 4s ago

Increasing the time to 25 seconds to give it a chance.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>
(cherry picked from commit de448ea2e88b01b99c0a2966dbb028f0fb4cfe59)