Cloud not clean up target directory typo'ed error message

[TelepathicGrunt]

Tiny typo I saw that was a bit funny to see.

Come from this line:

NeoGradle/utils/src/main/java/net/neoforged/gradle/util/CopyingFileTreeVisitor.java

Line 56 in 2d1add3

throw new RuntimeException("Cloud not clean up target directory: " + directory, e);

Cloud be cleaned up as a small side thing in a future NeoGradle update.