Bump stil4m/elm-syntax from 7.2.9 to 7.3.1

Bumps [stil4m/elm-syntax](https://github.com/stil4m/elm-syntax) from 7.2.9 to 7.3.1.
- [Changelog](https://github.com/stil4m/elm-syntax/blob/master/CHANGELOG.md)
- [Commits](stil4m/elm-syntax@7.2.9...7.3.1)

---
updated-dependencies:
- dependency-name: stil4m/elm-syntax
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

elm.json

@@ -21,7 +21,7 @@
             "elm-community/result-extra": "2.4.0",
             "elm-community/string-extra": "4.0.1",
             "eriktim/elm-protocol-buffers": "1.2.0",
-            "stil4m/elm-syntax": "7.2.9",
+            "stil4m/elm-syntax": "7.3.1",
             "the-sett/elm-syntax-dsl": "5.3.0",
             "turboMaCk/non-empty-list-alias": "1.3.1"
         },