Update tested versions in README

[martey]

Update the Wagtail, Django, and Python versions mentioned as being tested in the README based on the tox configuration.

This section previously used the greater-than-or-equal sign (>=) when the less-than-or-equal sign (<=) was intended. Because these symbols are potentially confusing, they have been removed.

[MrCordeiro]

I don't think this is required, unfortunately. Most minor versions are backwards compatible and we are quick to update this package when they're not.

[martey]

I agree with you that wagtailmenus is generally compatible with minor versions and that the testing section of the README does not need to include them. However, my changes are not related to minor versions and do not change how they are handled in this section.

I apologize for reopening this request, but the section is currently inaccurate. Right now, the README says that wagtailmenus is compatible with:

• Wagtail versions greater than or equal to 5.2
• Django versions greater than or equal to 5.1
• Python 3.9 to 3.12

The section does not include Python 3.13. Because of the use of the greater than or equal signs that I previously mentioned, the section will automatically claim compatibility with future major versions of Django or Wagtail when they are released.

I tried to make a minimal amount of changes to fix these problems and thought that they were straightforward and non-objectionable, but maybe I should have created an issue to discuss this first. There are a number of potential alternate solutions to fix the current issues, in order of my personal preference:

• removing the greater than or equal signs and adding Python 3.13 (these are the changes currently in this pull request)
• changing the greater than signs to less than signs (since future major versions might have breaking changes that will require major changes)
• adding Python 3.13 to the list of Python versions being tested (and ignoring the greater than or equal issue)
• adding a greater than or equal sign to the list of Python versions being tested (so that Python 3.13 is added)

Please let me know if you would prefer one of these alternate solutions, and I will update this pull request to match it. If you don't think the current inaccuracy of the section is a problem, feel free to close this request again - I won't reopen it a second time.

[MrCordeiro]

Changing the greater than signs to less than signs (since future major versions might have breaking changes that will require major changes) and adding Python 3.13 to the list of Python versions being tested sounds like the ideal solution to me.

Plus, it keeps the testing matrix up-to-date, which we would appreciate!