fix(spark): cap aiohttp<3.14 in test deps for aioresponses compat

[1fanwang]

Why are the changes needed?

The flytekit-spark build is red on master: aioresponses mocks a ClientResponse without the stream_writer argument that aiohttp 3.14 made required, and the plugin's test deps don't cap aiohttp (CI resolves 3.14.1).

What changes were proposed in this pull request?

Cap aiohttp<3.14 in plugins/flytekit-spark/dev-requirements.in (test-only) until aioresponses supports 3.14.

How was this patch tested?

Ran plugins/flytekit-spark/tests/test_connector.py in a fresh py3.12 venv that resolved the same deps as CI (aiohttp 3.14.1, aioresponses 0.7.8):

• Before: test_databricks_agent fails with TypeError: ClientResponse.__init__() missing 1 required keyword-only argument: 'stream_writer' (aioresponses/core.py:172) — the exact error CI hits.
• After: installing from the capped dev-requirements.in resolves aiohttp 3.13.5; all 14 tests pass. The InvalidSpecError seen later in the CI run was a cascade off that first failure (the test never reached mock.patch.stopall()), so it clears too.

Labels

fixed

Check all the applicable boxes

• I updated the documentation accordingly.
• All new and existing tests passed.
• All commits are signed-off.

[1fanwang]

Closing — pinning aiohttp only covers part of the spark build. It also fails on unrelated pyspark 4.x errors (test_wf / test_spark_task Py4J), so the pin can't green CI on its own.

Path forward: the plugin builds need a dependency re-pin, not per-test fixes — aiohttp<3.14 in setup.py (the -U install step re-resolves a dev-requirements.in pin away), plus a pyspark<4 cap.