fix(deps): update dependency io.camunda:zeebe-bom to v8.8.0-alpha6

Author: renovate[bot]

pom.xml

@@ -65,7 +65,7 @@
       <dependency>
         <groupId>io.camunda</groupId>
         <artifactId>zeebe-bom</artifactId>
-        <version>8.8.0-alpha5</version>
+        <version>8.8.0-alpha6</version>
         <type>pom</type>
         <scope>import</scope>
       </dependency>