Run buildkite clean as non-root

When using docker > 23 which uses buildkit by default, running `make
clean` creates a buildkit lock file as root which then causes later,
non-root builds to fail.

Signed-off-by: Kern Walster <[email protected]>

Author: Kern--

.buildkite/hooks/pre-exit

@@ -1,5 +1,5 @@
 #!/bin/bash
-sudo -E PATH=$PATH make -C "$BUILDKITE_BUILD_CHECKOUT_PATH" clean
+make -C "$BUILDKITE_BUILD_CHECKOUT_PATH" clean
 
 # clean up ephemeral files since this will cause an error to build kite due to
 # these files being owned by root