Fix for python version 3.10

[varad-ahirwadkar]

This PR includes fixes to run the vllm-tgis-adapter using python 3.10

Description

For Python versions earlier than 3.11, StrEnum is not included in the standard library enum. Therefore, it is downloaded and imported separately.
The delete=False parameter in tempfile.TemporaryDirectory() is supported only from Python 3.12 onwards. As a workaround, mkdtemp() is used instead.

How Has This Been Tested?

Env:

Python: 3.10
vLLM: v0.6.4.post2

Running tests:

pytest --disable-pytest-warnings tests/ | tee output.txt
============================= test session starts ==============================
platform linux -- Python 3.10.13, pytest-8.3.4, pluggy-1.5.0
rootdir: /workspace/vllm-tgis-adapter
configfile: pyproject.toml
plugins: twisted-1.14.3, mock-3.14.0, asyncio-0.25.0, anyio-4.6.2.post1
asyncio: mode=strict, asyncio_default_fixture_loop_scope=None
collected 71 items / 6 deselected / 65 selected

tests/test_adapters.py ......                                            [  9%]
tests/test_grpc_server.py ....s..                                        [ 20%]
tests/test_http_server.py ...                                            [ 24%]
tests/test_init.py .                                                     [ 26%]
tests/test_peft_converter.py .                                           [ 27%]
tests/test_termination_log.py ...                                        [ 32%]
tests/test_tgis_utils.py ............................................    [100%]

=========================== short test summary info ============================
SKIPPED [1] tests/test_grpc_server.py:64: Lora is not available with this configuration
===== 64 passed, 1 skipped, 6 deselected, 19 warnings in 173.80s (0:02:53) =====

Merge criteria:

• The commits are squashed in a cohesive manner and have meaningful messages.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[varad-ahirwadkar]

@dtrifiro Could you please review this PR? Thanks

[dtrifiro]

@varad-ahirwadkar we don't really test this with anything but 3.12. Is updating to 3.12 a choice?

[varad-ahirwadkar]

@varad-ahirwadkar we don't really test this with anything but 3.12. Is updating to 3.12 a choice?

Hi @dtrifiro,
Yes, will update to 3.12.
But are we considering support for Python 3.10 or 3.11?

[dtrifiro]

We thought we'd be supporting multiple python versions at first, but the reality is that we're going to be tied to whatever we have in the https://github.com/opendatahub-io/vllm ubi Dockerfile(s) (which currently is 3.12). We currently also run CI only for 3.12