Update the GH workflow branches for 0.18.x

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>

.github/workflows/conformance.yml

@@ -3,7 +3,7 @@ name: Conformance Tests
 on:
   pull_request: {}
   push:
-    branches: [main]
+    branches: [0.18.x]
   workflow_dispatch:
 
 jobs:

.github/workflows/docs.yml

@@ -3,7 +3,7 @@ name: Deploy Documentation
 on:
   push:
     branches:
-      - main
+      - 0.18.x
     paths:
       - 'docs/**'
       - 'mkdocs.yml'

.github/workflows/publish-snapshot.yml

@@ -2,7 +2,7 @@ name: Publish Snapshot
 
 on:
   push:
-    branches: [ "main", "0.18.x" ]
+    branches: [ "0.18.x" ]
 
 jobs:
   build: