Keep the api and ota noise keys in flash behind one context

tests/integration/test_host_ota.py

@@ -143,25 +143,13 @@ async def test_host_ota_encrypted(
             pid_before = proc.pid
 
             # A plaintext upload must be refused with the device unharmed
-            rc, _ = await loop.run_in_executor(
-                None, espota2.run_ota, LOCALHOST, ota_port, None, binary_path
-            )
+            rc = await _run_ota(ota_port, None, binary_path, None)
             assert rc == 1, "plaintext upload to an encrypted device must fail"
             await asyncio.sleep(0.5)
             assert proc.returncode is None, "process died on rejected plaintext OTA"
 
             # The encrypted upload goes through and the device re-execs
-            rc, _ = await loop.run_in_executor(
-                None,
-                functools.partial(
-                    espota2.run_ota,
-                    LOCALHOST,
-                    ota_port,
-                    None,
-                    binary_path,
-                    noise_psk=API_KEY,
-                ),
-            )
+            rc = await _run_ota(ota_port, None, binary_path, API_KEY)
             assert rc == 0, "encrypted OTA reported failure"
             await asyncio.wait_for(rebooted, timeout=10.0)
             await _wait_for_port(LOCALHOST, api_port, PORT_WAIT_TIMEOUT)