Bump org.codehaus.mojo:flatten-maven-plugin in /spi-fly

Bumps [org.codehaus.mojo:flatten-maven-plugin](https://github.com/mojohaus/flatten-maven-plugin) from 1.3.0 to 1.6.0.
- [Release notes](https://github.com/mojohaus/flatten-maven-plugin/releases)
- [Commits](https://github.com/mojohaus/flatten-maven-plugin/compare/flatten-maven-plugin-1.3.0...1.6.0)

---
updated-dependencies:
- dependency-name: org.codehaus.mojo:flatten-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/spi-fly/pom.xml b/spi-fly/pom.xml
index b0d1ebc..a2a3d17 100644
--- a/spi-fly/pom.xml
+++ b/spi-fly/pom.xml
@@ -164,7 +164,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>flatten-maven-plugin</artifactId>
-                <version>1.3.0</version>
+                <version>1.6.0</version>
                 <configuration>
                     <flattenMode>oss</flattenMode>
                 </configuration>