[PECOBLR-2461] fix(tests/e2e): de-collide MST table names across concurrent CI jobs

`_unique_table_name` derived the table name purely from the test node id,
so two CI runs racing on the same warehouse + catalog (e.g. PR + push to
main landing within seconds, as happened in run 26410038645) would both
target `peco.default.mst_pysql_<test_name>` and step on each other's
CREATE / DROP / DML. This caused the three "flaky" failures we kept
seeing in `test_transactions.py`:

  - test_multi_table_commit       → TRANSACTION_ROLLBACK_REQUIRED_AFTER_ABORT
  - test_executemany_rollback_in_txn → TABLE_OR_VIEW_NOT_FOUND
  - test_write_conflict_single_table → TABLE_OR_VIEW_ALREADY_EXISTS

The companion helper `_unique_table_name_raw` already appended a uuid4
suffix for exactly this reason; the fixture helper was an oversight from
#775. Add the same suffix here, reserving room so the result still fits
in the 80-char cap.

Co-authored-by: Isaac
Signed-off-by: Vikrant Puppala <vikrant.puppala@databricks.com>

Author: vikrantpuppala

tests/e2e/test_transactions.py

@@ -35,10 +35,17 @@
 
 
 def _unique_table_name(request):
-    """Derive a unique Delta table name from the test node id."""
+    """Derive a unique Delta table name from the test node id.
+
+    The uuid suffix keeps tables unique across concurrent CI jobs that
+    share the same warehouse/catalog — without it, two runs racing on
+    the same test name collide on CREATE/DROP.
+    """
     node_id = request.node.name
     sanitized = re.sub(r"[^a-z0-9_]", "_", node_id.lower())
-    return f"mst_pysql_{sanitized}"[:80]
+    suffix = uuid.uuid4().hex[:8]
+    # Reserve room for the 9-char "_{suffix}" tail so total stays <= 80.
+    return f"mst_pysql_{sanitized}"[:71] + f"_{suffix}"
 
 
 def _unique_table_name_raw(suffix):