Python: Fix GitHubCopilotAgent to include tools added by ContextProvider.before_run in session creation (#5780)

* Fix GitHubCopilotAgent ignoring tools from context providers (#5736)

_create_session and _resume_session only forwarded self._tools (constructor
tools) to CopilotClient.create_session, dropping any tools contributed by
context providers via session_context.extend_tools() during before_run.

Merge provider-contributed tools into runtime_options in both _run_impl and
_stream_updates before session creation, mirroring how RawAgent handles the
merge at lines 1435-1440 in _agents.py. Update _create_session and
_resume_session to combine self._tools with the merged runtime tools.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Python: Fix GitHubCopilotAgent to include tools added by ContextProvider.before_run in session creation

Fixes #5736

* Fix provider tool merge to avoid mutating caller's list

- Replace in-place .extend() with fresh list creation in both
  _run_impl and _stream_updates paths to prevent mutating the
  caller-provided options['tools'] list (shallow copy issue)
- Also handles immutable Sequence types (e.g. tuple) correctly
- Add test for provider tools forwarded via _resume_session path

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address review feedback for #5736: review comment fixes

---------

Co-authored-by: Copilot <copilot@github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

python/uv.lock

@@ -602,7 +602,7 @@ dependencies = [
 [package.metadata]
 requires-dist = [
     { name = "agent-framework-core", editable = "packages/core" },
-    { name = "github-copilot-sdk", marker = "python_full_version >= '3.11'", specifier = "<=1.0.0b2,>=1.0.0b2" },
+    { name = "github-copilot-sdk", marker = "python_full_version >= '3.11'", specifier = ">=1.0.0b2,<=1.0.0b2" },
 ]
 
 [[package]]