Bump eu.maveniverse.maven.nisse:extension from 0.8.3 to 0.8.4 (#1586)

Bumps [eu.maveniverse.maven.nisse:extension](https://github.com/maveniverse/nisse) from 0.8.3 to 0.8.4.
- [Release notes](https://github.com/maveniverse/nisse/releases)
- [Commits](https://github.com/maveniverse/nisse/compare/release-0.8.3...release-0.8.4)

---
updated-dependencies:
- dependency-name: eu.maveniverse.maven.nisse:extension
  dependency-version: 0.8.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.mvn/extensions.xml

@@ -4,6 +4,6 @@
     <extension>
         <groupId>eu.maveniverse.maven.nisse</groupId>
         <artifactId>extension</artifactId>
-        <version>0.8.3</version>
+        <version>0.8.4</version>
     </extension>
 </extensions>