remove invalid path pattern from push.branches in CI config

push.branches filters by branch name, not file paths. The sample directory
pattern added here had no effect. The pull_request.paths filter remains and
correctly triggers CI for this sample.

Author: wakata_sansan

.github/workflows/samples-kotlin-client.yaml

@@ -6,7 +6,6 @@ on:
       - 'samples/client/petstore/kotlin*/**'
       - 'samples/client/others/kotlin-jvm-okhttp-parameter-tests/**'
       - samples/client/others/kotlin-integer-enum/**
-      - samples/client/others/kotlin-oneOf-anyOf-kotlinx-serialization/**
   pull_request:
     paths:
       - 'samples/client/petstore/kotlin*/**'