Improve collection matching and upload options

[pjhartzell]

Summary:

• The changes in this PR provide deterministic order during collection assignment through use of an array rather than a map (order not guaranteed) and per-collection upload options (with the ability to add more per-collection configuration in the future).
• Along the way, the payload properties that were embedded in the Task class were extracted to a Payload class to separate concerns/data models.
• It's been a while since this repo has been updated, so this PR modernizes to use uv and updates CI and pre-commit. It also makes some extensive changes and additions to the README, gets readthedocs working, and makes a minimal changeset to the readthedocs content.
• Python 3.9 is EOL next month, so support is removed.
• All changes are backwards compatible...except the removal of Python 3.9.

Related Issue(s):

• Closes Collections should be an array? #124
• Closes Per collection upload options #174

Proposed Changes:

1. Extracts the payload data model from within the task model into a new Payload class.
2. Adds a collection_matchers array to the payload process block. Mutually exclusive with the legacy process.upload_options.collections map. This supports deterministic order in the pattern matching and directly supports a "catch_all" matcher, which is a common need.
3. Adds collection_options map to the payload process block. Supports collection-specific upload_options, with a fallback to the global process.upload_options if a collection is not found in the map.
4. Remove Python 3.9 support.

PR Checklist:

• I have added my changes to the CHANGELOG or a CHANGELOG entry is not required.

[ircwaves]

LGTM.

[jkeifer]

I left some comments that could result in changes if you so choose, but I am satisfied with the current state of everything (note: it was a bit hard to review all the changes because it looks like you pulled in a bunch of ruff rules that touched a lot of code 😅). Nothing I mentioned is really a deal breaker so do as you choose.