When I ask Copilot in Agent mode to add/remove breakpoints in a certain way to help debugging, it's telling me it can't do it and I need to manually click every line to add/remove the breakpoint when ...

This PR proposes to remove SPARK_CONNECT_MODE environment variable when starting Spark Connect server. So SparkSubmit thinks no remote is set in ord ... org.apache.spark.sql.connect.SparkConnectPlugin ...