Adds experimental support for uv.lock in ImageSpec

[thomasjpfan]

Why are the changes needed?

uv and uv.lock is becoming a commonly used tool for managing python environments. This PR adds experimental support for uv.lock into ImageSpec.

What changes were proposed in this pull request?

This PR enables requirements="uv.lock" support in ImageSpec. Using uv.lock shows a warning stating that uv.lock support is experimental since uv sync is experimental, so our integration may change.

How was this patch tested?

mkdir uv-check
cd uv-check
uv init
uv add flytekit numpy

# activate python environment with this PR
pyflyte run --remote main.py my_task

where main.py is:

from flytekit import task, ImageSpec

image_spec = ImageSpec(
    name="uv-wow",
    requirements="uv.lock",
    registry="localhost:30000",
    env={"abc": "xyz125"},
)


@task(container_image=image_spec)
def my_task() -> int:
    import numpy as np

    return np.asarray([1, 2, 3]).sum().item()