Strip all OH sandbox plugins (jupyter + agent_skills)

agent_skills indexes /workspace at startup, causing a 120s timeout on
large repos (firefox, linux, etc). We use a preamble for instructions
so the skills plugin isn't needed. Clearing sandbox_plugins entirely
fixes baseline ConnectError on all large-repo tasks.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sjarmak

agents/harnesses/openhands/agent.py

@@ -215,14 +215,12 @@ def create_run_agent_commands(self, instruction: str):
             "",
             "_preload_site_package('pandas')",
             "",
-            "# Monkey-patch CodeActAgent to exclude the jupyter plugin.",
-            "# OpenHands v1.4.0 hardcodes JupyterRequirement in sandbox_plugins",
-            "# and the jupyter-kernelgateway cannot bind inside Daytona sandboxes.",
+            "# Strip all sandbox plugins (jupyter, agent_skills).",
+            "# jupyter-kernelgateway can't bind in Daytona sandboxes, and",
+            "# agent_skills indexes /workspace at startup which times out on large repos.",
+            "# We use a preamble for task instructions, so skills aren't needed.",
             "import openhands.agenthub.codeact_agent.codeact_agent as _ca_mod",
-            "_ca_mod.CodeActAgent.sandbox_plugins = [",
-            "    p for p in _ca_mod.CodeActAgent.sandbox_plugins",
-            "    if getattr(p, 'name', '') != 'jupyter'",
-            "]",
+            "_ca_mod.CodeActAgent.sandbox_plugins = []",
             "",
             "runpy.run_module('openhands.core.main', run_name='__main__')",
         ])