Changelog can be generated with non-version tags as a header

[sacha-c]

Description

Changelogs should be generated only with version tags as headers. Tags are indeed being checked that they are version tags when generating the changelog here, but this logic is missing for the latest commit's tag.

This means that changelogs can be generated with an incorrect tag for the latest version

I've already opened a PR to fix this issue here, I hope that's okay and is useful! 🙂
I'm open to suggestions if you see anything to improve there of course

Steps to reproduce

On a project with commitizen setup

1. touch some-change
2. git commit -m "feat: some change"
3. git tag a-tag-that-has-nothing-to-do-with-versions
4. cz changelog --dry-run

See that the output is

## a-tag-that-has-nothing-to-do-with-versions (2023-05-10)

### Feat

- some change

instead of

## Unreleased
...

or

## 0.1.0 (2023-05-10)
...

Current behavior

Non-version tags can appear as the latest version header of the changelog

Desired behavior

Only version tags should ever appear in the changelog, for the latest change & subsequent changes

Screenshots

No response

Environment

Commitizen Version: 3.2.1
Python Version: 3.10.8 (main, Dec 27 2022, 10:58:47) [Clang 14.0.0 (clang-1400.0.29.202)]
Operating System: Darwin

[sacha-c]

Upon further research, I noticed that generating the changelog for specific versions, like so:
cz changelog --dry-run 3.2.0
Also gets incorrect results if there are non-version tags in the history. Basically the rev-range that is created from the initial tag stops at the next tag (in get_smart_tag_range), which isn't necessarily the next version tag.

I'll investigate a little more and add changes to my PR if I find a good way to fix this as well

[sacha-c]

I have updated my PR to include a fix for the above as well