REL: backport bilby-dev#960 to v2.5.2 (bilby-dev#961)

* BUG: fix the filename extension precedence for result files (bilby-dev#960)

* BUG: fix the filename extension precedence for result files

* Apply suggestions from code review

Co-authored-by: Michael J. Williams <michaeljw1@googlemail.com>

* FMT: add empty line

* TYPO: fix typo in warning

* FMT: remove extra whitespace

* BUG: move default extension fallback

---------

Co-authored-by: Michael J. Williams <michaeljw1@googlemail.com>

* CHANGELOG: prepare v2.5.2

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Co-authored-by: Colm Talbot <talbotcolm@gmail.com>

Author: mj-will

CHANGELOG.md

@@ -5,6 +5,12 @@ The original MRs are only visible on the [LIGO GitLab repository](https://git.li
 
 ## [Unreleased]
 
+## [2.5.2]
+
+### Fixed
+
+- Fix the filename extension precedence for result files (https://github.com/bilby-dev/bilby/pull/960)
+
 ## [2.5.1]
 
 ### Changed
@@ -1151,7 +1157,8 @@ First `pip` installable version https://pypi.org/project/BILBY/ .
 - All chainconsumer dependency as this was causing issues.
 
 
-[Unreleased]: https://github.com/bilby-dev/bilby/compare/v2.5.1...main
+[Unreleased]: https://github.com/bilby-dev/bilby/compare/v2.5.2...main
+[2.5.2]: https://github.com/bilby-dev/bilby/compare/v2.5.1...v2.5.2
 [2.5.1]: https://github.com/bilby-dev/bilby/compare/v2.5.0...v2.5.1
 [2.5.0]: https://github.com/bilby-dev/bilby/compare/v2.4.0...v2.5.0
 [2.4.0]: https://github.com/bilby-dev/bilby/compare/v2.3.0...v2.4.0