docs(spark): drop unverified "general HTTP connectivity 20.7+" row

The minimum ClickHouse version table claimed 20.7+ for general HTTP
connectivity, but I couldn't trace that to anything in the connector
code or ClickHouse release notes. The HTTP interface itself has been
present since the initial open-source release. The remaining two rows
(splitByPartitionId 21.6+, VariantType/JSON 25.3+) are feature-specific
and verified.

Author: ShimonSte

docs/integrations/data-ingestion/apache-spark/spark-native-connector.md

@@ -1583,7 +1583,6 @@ The connector communicates with ClickHouse exclusively over HTTP. There is no mi
 
 | Feature | Minimum ClickHouse Version |
 |---------|---------------------------|
-| General HTTP connectivity | 20.7+ |
 | `spark.clickhouse.read.splitByPartitionId` (partition-id-based filtering) | 21.6+ |
 | `VariantType` / `JSON` type support | 25.3+ |