Update dependency org.gitlab4j:gitlab4j-api to v6.0.0-rc.8

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

java-components/pom.xml

@@ -280,7 +280,7 @@
             <dependency>
                 <groupId>org.gitlab4j</groupId>
                 <artifactId>gitlab4j-api</artifactId>
-                <version>6.0.0-rc.7</version>
+                <version>6.0.0-rc.8</version>
             </dependency>
             <dependency>
                 <groupId>org.kohsuke</groupId>