Bump org.apache.maven.plugins:maven-dependency-plugin in /spi-fly

Bumps [org.apache.maven.plugins:maven-dependency-plugin](https://github.com/apache/maven-dependency-plugin) from 3.4.0 to 3.8.1.
- [Release notes](https://github.com/apache/maven-dependency-plugin/releases)
- [Commits](apache/maven-dependency-plugin@maven-dependency-plugin-3.4.0...maven-dependency-plugin-3.8.1)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-dependency-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

spi-fly/pom.xml

@@ -126,7 +126,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-dependency-plugin</artifactId>
-                    <version>3.4.0</version>
+                    <version>3.8.1</version>
                 </plugin>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>