Increase timeout for ProcessGroupGlooTest (pytorch#85474)

We see spurious failures due to timeouts in`test_allreduce_coalesced_basics` but only when running the whole test suite with
`python run_test.py --verbose -i distributed/test_c10d_gloo`. Increasing the timeout to 50s should provide enough leeway to avoid this. Note that the default for the `_timeout` is 30 minutes.

Originally reported in EasyBuild at easybuilders/easybuild-easyconfigs#15137 (comment) and patch proposed by @casparvl
Pull Request resolved: pytorch#85474
Approved by: https://github.com/rohan-varma

test/distributed/test_c10d_gloo.py

@@ -215,7 +215,7 @@ def setUp(self):
 
     def opts(self, threads=2):
         opts = c10d.ProcessGroupGloo._Options()
-        opts._timeout = 5.0
+        opts._timeout = 50.0
         opts._devices = [create_device(interface=LOOPBACK)]
         opts._threads = threads
         return opts