Add Python 3.14 to CI

[benclifford]

This PR begins testing against upcoming Python 3.14 to flush out issues ahead of time.

[benclifford]

first failure: cannot build pydantic:

        error: the configured Python interpreter version (3.14) is newer than PyO3's maximum supported version (3.13)
        = help: please check if an updated version of PyO3 is available. Current version: 0.24.1
        = help: set PYO3_USE_ABI3_FORWARD_COMPATIBILITY=1 to suppress this check and build anyway using the stable ABI

This dependency comes via Globus Compute, in the test environment, and it lookslike pydantic-core supports Python 3.14 as of pydantic/pydantic-core#1714 which I think is so far unreleased.

[benclifford]

proxystore also depends on pydantic so i've removed it from this branch, pending new pydantic

[benclifford]

now I see this test failing:

 Process Process-1:
Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.14.0-rc.1/x64/lib/python3.14/multiprocessing/process.py", line 320, in _bootstrap
    self.run()
    ~~~~~~~~^^
  File "/opt/hostedtoolcache/Python/3.14.0-rc.1/x64/lib/python3.14/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/parsl/parsl/parsl/tests/test_regression/test_854.py", line 12, in consumer
    x = in_q.get()
  File "/home/runner/work/parsl/parsl/parsl/multiprocessing.py", line 47, in get
    with self._counter.get_lock():
         ^^^^^^^^^^^^^
AttributeError: 'MacSafeQueue' object has no attribute '_counter'

I think this is because test_854.py uses Process, with the default multiprocessing launch type. which in Python 3.14 changed from fork to forkserver. and I think that means its possible that this class has been broken on macs for a while? because spawn has been used there, not fork for a long time. There's no testing of os x support.

[benclifford]

proxystore has a fairly loose bound on pydantic, so probably when a new pydantic is released, this dependency problem will be resolved and the proxystore tests can be restored.

[benclifford]

dill release 0.4.0 contains this python 3.14 support. uqfoundation/dill#691 which I take as implying earlier dills will not work properly with 3.14

globus compute pins an earlier dill (and I have noted that to the globus compute dev team on slack) and I wonder if that means the pin will propagate to the parsl test environment -- the test that passed ok, way above here ^, used dill 0.4.0 because GC was disabled in that build.

[benclifford]

on my laptop I have tested that dill < 0.4.0 breaks with Python 3.14 - a breakage that isn't directly visible in the tests are the moment, as dill < 0.4.0 only happens when Globus Compute is also installs, which breaks in a different way first.

[benclifford]

I just pushed changes to use Python 3.14.0, thinking that it was available based on my misreading of some other GitHub Actions documentation. But I'll leave it in place because presumably it soon will be -- Python 3.14 was released earlier today.