update banner severity (#584) (#616)

Author: jwilliams-mongo

snooty.toml

@@ -117,7 +117,7 @@ vpc = ":abbr:`VPC (Virtual Private Cloud)`"
 
 [[banners]]
 targets = ["command/atlas-dataLakePipelines*.txt"]
-variant = "info"
+variant = "warning"
 value = """\
     **Data Lake is deprecated.** \
     As of September 2024, Data Lake is deprecated and will reach end-of-life. It will be removed on September 30, 2025. If you use Data Lake, you should migrate to alternative solutions before the service is removed. To learn more, see :adl:`Migration Guide <data-lake-deprecation/>`\