feat(manager/kubernetes): strip go templates before parsing (#28816)

lib/modules/manager/kubernetes/__fixtures__/configmap.yaml

+{- if .Values.configMap.enabled | default false }
 apiVersion: v1
 kind: ConfigMap
 metadata:
@@ -5,3 +6,4 @@ metadata:
   labels:
     app: nginx
 data: {}
+{- end }

lib/modules/manager/kubernetes/extract.ts

@@ -71,7 +71,10 @@ function extractApis(
 
   try {
     // TODO: use schema (#9610)
-    doc = parseYaml(content);
+    doc = parseYaml(content, null, {
+      filename: packageFile,
+      removeTemplates: true,
+    });
   } catch (err) {
     logger.debug({ err, packageFile }, 'Failed to parse Kubernetes manifest.');
     return [];