[engsys] increase search live test pipeline timeout to 90 minutes (Azure#23305)

Recently the test resource deployment step for search live test pipeline can
take more than 40 minutes to finish, while the integration test step only takes
less than 10  minutes. We have contacted service team about deployment issue.

Still it is better to let the pipeline finish running than canceling the run after
all these time spent on test resource deployment.

Author: jeremymeng

sdk/search/search-documents/tests.yml

@@ -5,6 +5,7 @@ stages:
     parameters:
       PackageName: "@azure/search-documents"
       ServiceDirectory: search
+      TimeoutInMinutes: 90
       # TODO: change 'Preview' cloud back to public after search RP fixes deletion metadata issue
       Clouds: 'Preview'
       SupportedClouds: 'Preview,UsGov,China'