chore: adopt granular API-level mixins syntax in librarian.yaml (googleapis#8677)

Author: quirogas

librarian.yaml

@@ -611,12 +611,15 @@ libraries:
     version: 5.2.2
     apis:
       - path: google/cloud/datacatalog/v1
+        nodejs:
+          mixins: none
       - path: google/cloud/datacatalog/v1beta1
+        nodejs:
+          mixins: none
     copyright_year: "2026"
     nodejs:
       default_version: v1
       main_service: DataCatalog
-      mixins: none
   - name: google-cloud-datacatalog-lineage
     version: 2.2.0
     apis:
@@ -662,10 +665,11 @@ libraries:
     version: 5.6.0
     apis:
       - path: google/cloud/dataplex/v1
+        nodejs:
+          mixins: google.cloud.location.Locations;google.longrunning.Operations
     copyright_year: "2026"
     nodejs:
       default_version: v1
-      mixins: google.cloud.location.Locations;google.longrunning.Operations
       client_documentation_override: https://cloud.google.com/dataplex
   - name: google-cloud-dataproc
     version: 6.6.0
@@ -725,12 +729,15 @@ libraries:
     version: 5.8.2
     apis:
       - path: google/cloud/dialogflow/cx/v3
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations
       - path: google/cloud/dialogflow/cx/v3beta1
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations
     copyright_year: "2026"
     skip_generate: true
     nodejs:
       default_version: v3
-      mixins: google.longrunning.Operations;google.cloud.location.Locations
   - name: google-cloud-discoveryengine
     version: 2.7.0
     apis:
@@ -813,14 +820,21 @@ libraries:
     version: 4.2.2
     apis:
       - path: google/cloud/functions/v2
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations;google.iam.v1.IAMPolicy
       - path: google/cloud/functions/v1
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations
       - path: google/cloud/functions/v2beta
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations;google.iam.v1.IAMPolicy
       - path: google/cloud/functions/v2alpha
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations;google.iam.v1.IAMPolicy
     copyright_year: "2026"
     skip_generate: true
     nodejs:
       default_version: v1
-      mixins: google.longrunning.Operations;google.cloud.location.Locations
   - name: google-cloud-gdchardwaremanagement
     version: 0.10.1
     apis:
@@ -1280,12 +1294,17 @@ libraries:
     version: 4.4.0
     apis:
       - path: google/cloud/retail/v2
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations
       - path: google/cloud/retail/v2beta
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations
       - path: google/cloud/retail/v2alpha
+        nodejs:
+          mixins: google.longrunning.Operations;google.cloud.location.Locations
     copyright_year: "2026"
     nodejs:
       default_version: v2beta
-      mixins: google.longrunning.Operations;google.cloud.location.Locations
   - name: google-cloud-run
     version: 3.3.0
     apis: