Drop support for awkward v1

[Saransh-cpp]

Description

Kindly take a look at CONTRIBUTING.md.

Please describe the purpose of this pull request. Reference and link to any relevant issues or pull requests.

Checklist

• [ ] Have you followed the guidelines in our Contributing document?
• [ ] Have you checked to ensure there aren't any other open Pull Requests for the required change?
• [ ] Does your submission pass pre-commit? ($ pre-commit run --all-files or $ nox -s lint)
• [ ] Does your submission pass tests? ($ pytest or $ nox -s tests)
• [ ] Does the documentation build with your changes? ($ cd docs; make clean; make html or $ nox -s docs)
• [ ] Does your submission pass the doctests? ($ pytest --doctest-plus src/vector/ or $ nox -s doctests)

Before Merging

• [ ] Summarize the commit messages into a brief review of the Pull request.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 90.90909% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 82.79%. Comparing base (23f1c42) to head (af9000a).

Files	Patch %	Lines
src/vector/__init__.py	50.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #434 +/- ## ========================================== + Coverage 82.77% 82.79% +0.02% ========================================== Files 96 96 Lines 11583 11575 -8 ========================================== - Hits 9588 9584 -4 + Misses 1995 1991 -4 ```

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[Saransh-cpp]

Thanks for the review! That makes sense, I'll create a new branch before merging the PR. I think I'll hold this till coffea migrates to vector as the process has already changed several things in vector.

[Saransh-cpp]

Now that coffea has switched to vector and the changes are up in a release, it should be okay to merge this in. I will wait for a couple of weeks before merging this, just in case we get some suggestions from coffee users. I think pyhep.dev would be the perfect place to merge this in and create a new release.