Ignore trailing / in host name

The trailing / is often added automatically when copy pasting
Before this change, you would get "Database Error - failed to connect"

After this change, the trailing backslash won't prevent your connection

dbt/adapters/spark/connections.py

@@ -140,6 +140,9 @@ def __post_init__(self):
                     f"ImportError({e.msg})"
                 ) from e
 
+        if self.method != SparkConnectionMethod.SESSION:
+            self.host = self.host.rstrip("/")
+
     @property
     def type(self):
         return "spark"