fix pmd law-of-demeter in ruleset

Author: Benjosh95

config/pmd/pmd-ruleset.xml

@@ -35,7 +35,10 @@
         <exclude name="OnlyOneReturn"/>
     </rule>
 
+    <!-- Excluded this rule to allow simple behaviour like parameter.method() 
+    or chained getter calls (transversing dtos) -->
     <rule ref="category/java/design.xml">
+        <exclude name="LawOfDemeter"/>
     </rule>
 
     <rule ref="category/java/documentation.xml">

core/src/main/java/cloud/stackit/sdk/core/auth/SetupAuth.java

@@ -6,6 +6,7 @@
 import cloud.stackit.sdk.core.config.EnvironmentVariables;
 import cloud.stackit.sdk.core.exception.CredentialsInFileNotFoundException;
 import cloud.stackit.sdk.core.exception.PrivateKeyNotFoundException;
+import cloud.stackit.sdk.core.model.ServiceAccountCredentials;
 import cloud.stackit.sdk.core.model.ServiceAccountKey;
 import cloud.stackit.sdk.core.utils.Utils;
 import com.google.gson.Gson;