chore: remove Python 3.9 EKS E2E test

[ezhang6811]

Issue #, if available:

Description of changes:
The urllib3 dependency release 2.7.0 requires Python 3.10+. Our python EKS test builds the image from Python 3.11 and then fails when injected into a Python 3.9 container with the following type error:

File "/otel-auto-instrumentation-python/urllib3/_base_connection.py", line 10, in <module>
    bytes, typing.IO[typing.Any], typing.Iterable[bytes | str], str
TypeError: unsupported operand type(s) for |: 'type' and 'type'

We will drop this test as Python 3.9 is EOL and upstream has already dropped 3.8 support. We will officially drop Python 3.9 support ahead of the next major/minor release.

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