ci: exclude testdata from sonar.exclusions (#26398)

Signed-off-by: reggie-k <[email protected]>

Author: reggie-k

sonar-project.properties

@@ -8,7 +8,8 @@ sonar.projectVersion=1.0
 # Path is relative to the sonar-project.properties file. Replace "\" by "/" on Windows.
 sonar.sources=.
 
-sonar.exclusions=docs/**
+# Exclude docs and testdata with kustomization files (Sonar IaC parser fails on empty/edge-case YAML)
+sonar.exclusions=docs/**,**/testdata/**
 
 # Encoding of the source code. Default is default system encoding
 sonar.sourceEncoding=UTF-8