fix(e2e): add /dev/urandom to provider test sandbox policy (#948)

Python runtime requires /dev/urandom access during initialization
to seed the hash randomizer. The _default_policy() in provider tests
was missing this path, causing exec_python tests to fail with:
'Fatal Python error: _Py_HashRandomization_Init: failed to get
random numbers to initialize Python'.

Add /dev/urandom to read_only paths to match the policy used in
test_sandbox_policy.py, allowing Python to initialize successfully.

Signed-off-by: Derek Carr <decarr@redhat.com>

Author: derekwaynecarr

e2e/python/test_sandbox_providers.py

@@ -36,7 +36,7 @@ def _default_policy() -> sandbox_pb2.SandboxPolicy:
         version=1,
         filesystem=sandbox_pb2.FilesystemPolicy(
             include_workdir=True,
-            read_only=["/usr", "/lib", "/etc", "/app"],
+            read_only=["/usr", "/lib", "/etc", "/app", "/dev/urandom"],
             read_write=["/sandbox", "/tmp"],
         ),
         landlock=sandbox_pb2.LandlockPolicy(compatibility="best_effort"),