Let dependencies in the pyproject.toml float upwards to reduce depencency version conflicts

[uckelman-sf]

Let dependencies in the pyproject.toml float upwards to reduce conflicts when using capa as a library. Added requirements.txt to continue pinning dependency versions for release builds.

Resolves #2053.

Checklist

• No CHANGELOG update needed

• No new tests needed

• No documentation update needed

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[github-actions]

Please add bug fixes, new features, breaking changes and anything else you think is worthwhile mentioning to the master (unreleased) section of CHANGELOG.md. If no CHANGELOG update is needed add the following to the PR description: [x] No CHANGELOG update needed

[williballenthin]

overall looks good, with a few recommendations inline.

thanks @uckelman-sf!

[williballenthin]

would you please add a comment that indicates something like "the following minimum dependency versions were imported in May 2024".

then if we have to bump some versions up, or otherwise restrict, we can move those to another section so that it's clear which are "hard" lower limits and which happen to be snapshots from today.

does this make sense? open to discussion.

[uckelman-sf]

Yeah, makes sense.

[sf-jonstewart]

Howdy! I... reaaaaaaaaaaalllllllllllllly... don't want to take three months of conference calls to sign a stupid CLA for some greater-than signs. Please consider this a well-specified bug report. :-)