Dependency(deps): Bump spoon.version

Bumps `spoon.version` from 11.1.1-beta-20 to 11.1.1-beta-21.

Updates `fr.inria.gforge.spoon:spoon-core` from 11.1.1-beta-20 to 11.1.1-beta-21

Updates `fr.inria.gforge.spoon:spoon-javadoc` from 11.1.1-beta-20 to 11.1.1-beta-21
- [Release notes](https://github.com/INRIA/spoon/releases)
- [Changelog](https://github.com/INRIA/spoon/blob/master/jreleaser.yml)
- [Commits](INRIA/spoon@v11.1.1-beta-20...v11.1.1-beta-21)

---
updated-dependencies:
- dependency-name: fr.inria.gforge.spoon:spoon-core
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: fr.inria.gforge.spoon:spoon-javadoc
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

pom.xml

@@ -54,7 +54,7 @@
 
         <slf4j.version>2.0.16</slf4j.version>
         <jackson.version>2.18.0</jackson.version>
-        <spoon.version>11.1.1-beta-20</spoon.version>
+        <spoon.version>11.1.1-beta-21</spoon.version>
         <fluent.version>0.70</fluent.version>
         <reflections.version>0.10.2</reflections.version>