ci-changelog expects specific toml format for fragment definitions
## Summary
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Changelog test requires pyproject.toml formatting different to pre-commit tool pyproject-fmt
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/cc @mlinhoff
/cc @dmorcuende
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SimPipe is using the pre-commit tool [pyproject-fmt](https://github.com/tox-dev/toml-fmt/tree/main). A recent update to the formatting process is incompatible with the changelog test (requiring `tool\.towncrier\.fragment\.' ${TOWNCRIER_CONFIG}`), while now there is a single section per tool, e.g.
```
[tool.towncrier]
package = "simpipe"
directory = "docs/changes"
filename = "CHANGELOG.rst"
underlines = [ "-", "~", "^" ]
template = "docs/changes/template.rst"
issue_format = "`!{issue} <https://gitlab.cta-observatory.org/cta-computing/dpps/simpipe/simpipe/-/merge_requests/{issue}>`__"
start_string = ".. towncrier release notes start"
fragment.api.name = "API Changes"
fragment.api.showcontent = true
...
```
I do actually thing this was a good update of the pyproject-fmt tool and it increases the readability of the project files.
Would require a small update to the test to get the test working with the new format.
issue