Ignore OSErrors on subprocess call of bjobs

Pretend these kinds of issues are flaky.

src/ert/scheduler/lsf_driver.py

@@ -444,9 +444,10 @@ async def poll(self) -> None:
                     stdout=asyncio.subprocess.PIPE,
                     stderr=asyncio.subprocess.PIPE,
                 )
-            except FileNotFoundError as e:
+            except OSError as e:
                 logger.error(str(e))
-                return
+                await asyncio.sleep(self._poll_period)
+                continue
 
             stdout, stderr = await process.communicate()
             if process.returncode:

tests/ert/unit_tests/scheduler/test_lsf_driver.py

@@ -1269,6 +1269,32 @@ def mock_poll_once_by_bhist(*args, **kwargs):
     assert job_id in driver._bhist_cache
 
 
+async def test_no_exception_when_bjobs_does_not_exist(caplog, job_name):
+    """The intent of this test is to ensure the driver will not
+    go down if the filesystem is temporarily flaky."""
+    driver = LsfDriver(bjobs_cmd="/bin_foo/not_existing")
+    driver._poll_period = 0.01
+    await driver.submit(0, "sh", "-c", "sleep 1", name=job_name)
+    with pytest.raises(asyncio.TimeoutError):
+        await asyncio.wait_for(driver.poll(), timeout=0.1)
+    assert "No such file or directory: '/bin_foo/not_existing'" in caplog.text
+
+
+@pytest.mark.integration_test
+async def test_no_exception_when_no_access_to_bjobs_executable(
+    not_found_bjobs, caplog, job_name
+):
+    """The intent of this test is to ensure the driver will not
+    go down if the filesystem is temporarily flaky."""
+    driver = LsfDriver()
+    driver._poll_period = 0.01
+    Path("bin/bjobs").chmod(0x0)  # Modify the bjobs from the fixture
+    await driver.submit(0, "sh", "-c", "echo", name=job_name)
+    with pytest.raises(asyncio.TimeoutError):
+        await asyncio.wait_for(driver.poll(), timeout=0.1)
+    assert "Permission denied" in caplog.text
+
+
 @pytest.mark.integration_test
 async def test_that_kill_before_submit_is_finished_works(tmp_path, monkeypatch, caplog):
     """This test asserts that it is possible to issue a kill command