Fix formatting bwc project excludes (elastic#79743)

This fixes a typo still causing elastic#79606 to fail

Author: breskeby

build-conventions/src/main/java/org/elasticsearch/gradle/internal/conventions/precommit/FormattingPrecommitPlugin.java

@@ -119,7 +119,7 @@ private Object[] getTargets(String projectPath) {
         ":client:test",
         ":distribution:archives:integ-test-zip",
         ":distribution:bwc:bugfix",
-        ":distribution:bwc:bugfix",
+        ":distribution:bwc:maintenance",
         ":distribution:bwc:minor",
         ":distribution:bwc:staged",
         ":distribution:docker",