Remove the assertion on partition key path in CosmosDBVectorStore constructor

Signed-off-by: Soby Chacko <soby.chacko@broadcom.com>

Author: sobychacko

vector-stores/spring-ai-azure-cosmos-db-store/src/main/java/org/springframework/ai/vectorstore/cosmosdb/CosmosDBVectorStore.java

@@ -107,7 +107,6 @@ protected CosmosDBVectorStore(Builder builder) {
 		Assert.notNull(builder.cosmosClient, "CosmosClient must not be null");
 		Assert.hasText(builder.containerName, "Container name must not be empty");
 		Assert.hasText(builder.databaseName, "Database name must not be empty");
-		Assert.hasText(builder.partitionKeyPath, "Partition key path must not be empty");
 
 		this.cosmosClient = builder.cosmosClient;
 		this.containerName = builder.containerName;