remove unnecessary parametrize cases in integration tests "multiple_sessions_in_parallel"

Motivation: These 2 integration tests are related to session management. It checks everything work as expected when multiple sessions are alive in parallel on same record. These tests were parametrize to check over different data format (JSON/parquet) and entity types (WellLog, Trajectory, Log) and then leads to 6 distinct combinations data format/entity type each (so 12 tests in total). Testing all these combination doesn't provide any plus value since it only on session management really matters. Moreover there are dedicated tests to check on all entity types and format.

Since these tests are quite long to execute (between 30s and 20s on dev env), it adds 5 minutes to complete the full integration test set without providing value.

The change here is to only keep one occurrence of each saving 4-5 minutes on pipeline per environment.