fix: add hacky workaround for near unix time timestamps on windows

[AstreaTSS]

Pull Request Type

• Feature addition
• Bugfix
• Documentation update
• Code refactor
• Tests improvement
• CI/CD pipeline enhancement
• Other: [Replace with a description]

Description

On Windows, timestamps in the range [0, 86400) ([ being inclusive, ) exclusive) do not function properly, as seen here: python/cpython#107078
Negative values have straight up never worked on Windows either, but it results in a weird error.

This PR does a bit of trickery to get the timestamps in the range of [0, 86400) working on Windows, at least to an extent where it doesn't error and is mostly correct.

Changes

• Add a negative timestamp check for fromtimestamp on Windows. This results in a clearer error than what Python would provide.
• Add in a custom astimezone function that makes timestamps in the range [0, 86400) work correctly with it. It does this by using the timezone of a slightly later date.

Related Issues

A more proper fix to one part of #1625. It's not a complete fix for the bug that caused the PR in the first place (since ActivityTimestamp's parsing results in incorrect behavior), but it'll make things not error out, at least.

Test Scenarios

Timestamp.fromtimestamp(0) to Timestamp.fromtimestamp(86399). You will need a Windows environment to test this.

Python Compatibility

• I've ensured my code works on Python 3.10.x
• I've ensured my code works on Python 3.11.x

Checklist

• I've run the pre-commit code linter over all edited files
• I've tested my changes on supported Python versions
• I've added tests for my code, if applicable
• I've updated / added documentation, where applicable